scientists are watching how an ecosystem can grow from nothing. >> anything biological that was remaining after the landslide would've been completely vaporized. it was just a barren landscape, gray and pumice colored, covered with rocks. >> woodruff: all that and more, on tonight's pbs newshour. >> major funding for the pbs newshour has been provided by: >> ♪ love me tender ♪ love me true we can like many, but we can love only a precious few. because it is for those precious few that you have to be willing to do so very much. but you don't have to do it alone. lincoln financial helps you provide for and protect your financial future, because this is what you do for people you love. lincoln financial-- you're in charge. >> fathom travel, offering cruises to cuba and the dominican republic. travel deep. >> bnsf railway. >> genentech. >> supported by the john d. and catherine t. macarthur foundation. committed to building a more just, verdant and peaceful world. more information at macfound.org >> and with the ongoing support of these institutions: >> this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. >> woodruff: the federal regulations governing overtime pay are changing for the first time since 2004. the u.s. labor department says its final rule, issued today, will be a boon to middle- and lower-income workers. business groups say in fact, it's going to hurt those very employees. the new rule means another 4.2 million workers will be eligible for overtime pay. vice president joe biden hailed the move at an event today in columbus, ohio. >> we've got to right this ship, and this is a very important piece of doing it because millions of people are going to start to get paid-- not more than they deserve-- what they deserve. and mark my words, the benefits are going to be beyond the compensation. >> woodruff: under the change, the salary threshold to qualify for time-and-a-half pay goes from $23,660 dollars a year to more than $47,000 dollars. the obama administration says it will boost wages by $12 billion over the next decade. thanks mainly to inflation, the number of full-time workers who currently qualify for overtime has plunged sharply, from 62% in 1975 to just 7% today. the restaurant and retail industries will see the greatest effects from the new regulation-- and they're strongly opposed. david french is with the national retail federation. >> by executive fiat, the administration is effectively demoting millions of workers from salaried exempt employment to hourly and likely non-exempt employment. in the real world, these changes are not going to benefit the workers they are promising overtime to. this is really a bait and switch. >> woodruff: some university officials have also warned they may have to raise tuition or scale back services to abide by the new guidelines. and in a statement today, republican house speaker paul ryan vowed to fight the overtime rule. he said: "this regulation hurts the very people it alleges to help." "many small businesses and non- profits will be unable to afford skilled workers and be forced to eliminate salaried positions." the rule takes effect december 1st. after that, the salary threshold will be automatically updated every three years. we'll have an interview with the secretary of labor, right after the news summary. in the presidential campaign, republican donald trump put out a list of people he'd consider nominating for the u.s. supreme court if he's elected president. he named 11 federal and state judges-- eight men and three women, all of them white. in a statement, trump said the list is "based on constitutional principles with input from highly respected conservatives and republican party leadership." the nation's top intelligence official warns that foreign hackers are spying on presidential candidates. james clapper, the national intelligence director, says there've been signs of cyber- attacks on the campaigns, as there were in 2008 and 2012. his office said the motives range from philosophical differences to espionage. there is word from nigeria that the first of the "chibok" girls has been found. the military says she was rescued yesterday in a remote forest, with a baby. more than 200 girls were abducted by "boko haram" militants just over two years ago. none has been seen since, until now. the rescued girl says a few have died, but most are still captive. to asia now and in sri lanka, rescuers used sticks and even bare hands today to dig for victims and survivors after mountains of mud buried their homes. more than 220 families were missing in a hard-hit district, located in the central part of the island nation. olivia kinsley of independent television news reports. >> reporter: another life claimed by these massive mudslides, caused by torrential rain that has been hammering sri lanka for days. hundreds of thousands of people have had to abandon their homes. entire villages have been buried, bodies are being pulled from the mud. those still alive, and still stranded, are being rescued one by one. >> reporter: with more rain on the way, they're putting out sandbags in the towns, but for low lying villages, the water and the devastation has been unstoppable. with rescuers struggling to reach those in some of the worst affected areas, the death toll will surely continue to rise. >> woodruff: search parties found 17 bodies before they suspended operations for the night. china today played down ongoing military exercises along its coast, facing taiwan. the defense ministry said the drills are not aimed at any specific target. they began just days before taiwan inaugurates a new president, who leans toward independence. beijing regards taiwan as a renegade province, and has never ruled out using force to bring it back into the fold. the chinese also condemned a u.s. move to slap duties of more than 500% on imported flat steel. it is used in car bodies and appliances, and china has a glut of it. the u.s. says beijing is dumping the steel and hurting american firms. and on wall street, the dow jones industrial average lost three points to close at 17,526. the nasdaq rose 23 points, and the s&p 500 added a fraction. still to come on the newshour: millions more eligible for overtime under new labor standards; documented atrocities in an isis stronghold in libya; billions of dollars later, why v.a. wait times are actually getting worse, and much more. >> woodruff: let's return to one of the biggest moves made by the obama administration to affect americans' take-home pay-- the new rules on overtime. many others consider previously exempt from overtime. william brangham interviewed the secretary of labor from the white house earlier today. >> reporter: welcome, secretary perez. why this change? and exactly what kinds of workers are you trying to help? >> sure. this change is designed to forth fie two basic-- forth i fie foo pilars of-- number one is middle class jobs should pay a middle class wage and number two, when you work extra, you should be paid extra. and the problem we're solving here, william, is that over the course of time, the threshhold, that differentiated people who were exempt employees, that is exempt from overtime eligibility versus people who are overtime eligible t hasn't kept up with the cost of living. and so it has really, really diminished its purchasing poker with. and secondly in 2004, the bush administration issued a new rule. and they frankly took virtually all the leverage away from workers an gave it to businesses. and that's why you have workers working 70 hours a week managing retail stores and other stores, and making $25, $30,000 a year which is basically at minimum wage. we're trying to fix that problem by doubling the threshhold from 23,000 to $47,000 and change. >> reporter: a number of industry groups have crittized-- criticized these rules am i would like to address the concerns. one is the employees will reclassified some salary workers into hourly workers to avoid paying them the overtime. they argue these rules could then mean a demotion for millions of workers. >> well, actually, i just met with a group of people, the vice president and i in ohio. a remarkable employer that has 600 employees, national footprint, and actually one of the things he did, was he converted their managers to hourly employees and guess what happened. they're making more money. and when you talk to their employees who are managers, who are making more money, they fell pretty good about themselves. and so this notion that suddenly workers are going to feel diminished stature, we did a lot of outreach on this. and you know,s that-- that wasn't our experience. and employers have a lot of flexibility. if you are making $40,000 now and the new threshhold is $47,476, you can still call that worker a salaried $40,000 employee who's overtime eligible. so they are still a salaried employee. the business owner that the vice president and i met with, they made a different choice and it worked for their workers. flexibility is the watchword of the fair labor standards act. and this new overtime rule. so employers have plenty of options. >> reporter: will is another concern that employers might cut back a worker's hours to avoid paying them overtime or they might just lower wages to compensate if they have to pay it. could these rules end up triggering a pay cut? >> well, you know, in 2004 there was the rule put in place by the bush administration and employers were faced with this. and i hear this criticism that actually they're going to reduce their wages. well, then it stands to reason that that should have happened in 2004 as well. but at least to the best of my knowledge it didn't. and here's why it didn't then and it won't now. these are the most valuable employees in many people's workforces. they open this stoor, they close the store, they hire, they fire. they go to the bank and deposit the money. they are the glue that keeps the organization together. rational employers don't take the glue that keeps the organization together and then cast them avoid. and that's inconsistent with a sound business practice. and so i appreciate the concerns, but you know, the employee is out of balance because so many managers have lost their leverage. and we're trying to restore that leverage. >> reporter: i mean it's not just industry that has raised questions. some leaders in higher education an nonprofits have also expressed a fear to what this could do to their workforce as well. >> well, we've done a lot of discussion with higher ed. and what they learned when we would discuss this issue with them is they have remarkable amounts of flexibility that they were unaware of. we had someone from higher ed say oh my god, my teachers work 70 hours a week and now have i to pay them overtime. actually that's not true, bawt the fair labor standards act exempts teachers, research assistants, wide categories of employees. i heard from a public university about all the challenges of compliance but they were unaware of the fact that public university can give comp time in lew of overtime pay for these workers. an when they heard that, you should have seen them, the light bull be went off. so i think there is a pretty good road map for compliance for folks in higher ed. and i would note this, william, which is that you know, over 50% of the 4.2 million workers who are going to directly benefit from this rule have a college degree. and ever 80% v some college. i always thought the mission of higher ed was to help prepare workers so that they can be productive citizens and punch their ticket to the middle class. so you know, it's a little inconsistent to have that mission and then say well, hey, wait a minute, we shouldn't be raising wages of our graduates. especially when i see the salaries of like the football coach at a couple of the universities that came to talk to us-- us to. when you pay them five, six, seven million dollars a year, you ought to be able to anything out a way to make sure that the person who manages the cafeteria in one of your halls can get a middle class salary. >> reporter: all right, labor secretary thomas perez, thanks very much for joining us. >> thank you. >> woodruff: now, to libya. chaos has gripped the north african nation since the fall of moammar gaddafi, with at least two governments and multiple factions simultaneously vying for power. now, there's word of wholesale atrocities by islamic state forces in the coastal city of sirte. fighter jets, flying for libya's u.n.-backed government, are bombing around sirte, and allied ground forces are pushing back as well, to stop islamic state militants from expanding beyond their stronghold there. 120 miles of the central libyan coastline, in and around sirte, has been under the militant group's control since early 2015. nearly two-thirds of sirte's 80,000 people have fled, and been forced to rely on humanitarian aid. >> ( translated ): the nationalities of isis fighters are all foreign-- tunisians, egyptians, sudanese. they came in and created a state of fear and terror for the people and families, so we fled. and they're all foreigners, none of them are libyans. we fled with nothing. >> woodruff: now come disturbing details of what's happening inside sirte, in a "human rights watch" report based on interviews with those who left. it tells of dozens of beheadings by sword, floggings and crucifixions, fathers forced to "marry off their daughters" to isis fighters, and all females over the age of ten forced to wear the conservative black cloak, the abbaya. on monday in vienna, secretary of state john kerry announced an agreement to arm the internationally recognized government in the fight against isis, also called daesh: >> the international community will support the presidency council as it seeks exemption from the u.n. arms embargo to acquire those weapons and bullets needed to fight daesh and other terrorist groups. >> woodruff: but it won't be easy. the u.s. commander in africa, general david rodriguez, said yesterday it's hard to tell which of many armed groups have aligned with the u.n. supported regime and which have not. we take a closer look at those groups and what the united states is doing in libya. i'm joined now by frederic wehrey of the middle east program at the carnegie endowment for international peace. he was a military attache to the u.s. embassy in tripoli during the george w. bush administration and he visits the country regularly. welcome back. remind us again how libya got to the state, two warring governments the same time, multiple fighting groups. >> ever since the fall of quad ar-- qaddafi there is a governance faction. the country split into civil war, two government, two sets of militias, there is this new u.n. unit government in tripoli that is still very week but the eastern faction doesn't recognize it. so you have this vacuum and that is a ripe condition for the islamic state toin setter itself as they have in the town of cert. >> woodruff: so how strong is isis, in libya right now. >> the estimates are about 3,000 to 6,000 fighters bolstered by foreign volunteers from abroad. and they control about 120 miles on the trip of coastline in the center. >> woodruff: and how big a threat does that represent given everything else going on in libya? >> it's destabilizing to the country's growth. it's also a threat to europe. and especially neighboring states. we've seen the islamic state in libya plot attacks against neighboring tunisia. >> woodruff: so let's back off a little bit here and go back to the role of the united states. you just mentioned nato. what does this mean? the u.s. was out of libya, then it was in, out. where is the u.s. right now in libya? >> well, the u.s. is really behind this new unity government in tripoli. and they are obviously to used-- focused on the islamic state threat. i think more broadly the u.s. wants to insure that this government succeeds. that we don't repeat the mistakes we made after the fall of qaddafi. but the first priority is protecting this government and then helping it fight the islamic state. and i think that's going to be done through some training, through assistance, through the lifting of the arms embargo as we heard. >> woodruff: but we heard secretary kerry say the u.s. is going to be arming the right government. but we also heard the general say it's not clear which group is which, on which side. how confusing is it? >> it very confusing. this is the problem we facial in all the states, who do you partner with. in the case of libya, there is no union fie government, chain of command or army. you have to pick among these militias and it is a dangerous game. you don't know who you are dealing with. they may turn against you or one another. a great risk is that by arming then we could actually fuel the civil war. i think the general is very right in proceeding quite carefully. >> woodruff: how do you do that? how does the united states do that? >> there have been reports now of u.s. speks operations on the ground. and what they are troo trying to do is assess these militias, their capacity, their will who are they aligned w before they begin training and assisting them. but you have to vet them for human rights violations, you have to recruit the right ones and make sure they are under the control of a democratic government. >> woodruff: what do you think should be done, is it your sense that this is a formula that is going to move in the right direction? >> i think the u.s. has learned a great deal from the mistakes they made. and i think they're proceeding quite cautiously. i think the right approach is to really support the legitimacy of this new government. this has to be a libyan led fight. one of the things that really amazed me when i was in libya was the amount of sort of societial resilience in libya against the islamic state. this was a foreign entity. people don't want it the libyans want to move forward with their government, with their employee. so the u.s. has to harness that momentum. >> woodruff: now that's what i was trying to get at. we see isis a factor in so many countries in the region. how do you tell the difference between countries where isis can overwhet am what is on the ground there, and where the forces against it can be stronger. >> yeah, i mean i think we shouldn't be overly alarmist about the islamic state in libya. i mean they are sort of boxed in the central region. they request still do a lot of damage. but it's not to the extent that they are in iraq, say, or syria. >> woodruff: bottomline, fred wehrey, what is at stake here for the united states? >> i think what is at stake is the success of the sort of toppling of the qaddafi government. i mean the security of important allies in the region, the security of europe. it's all wrapped up together. so there is a lot at stake. >> woodruff: and europe is very much a part of this. i haven't asked you this. >> they are, they are directly feaked by it. there are reports of. >> because of refugees. >> and also the potential plotting of terrorist attacks on libyan soil against europe. so the french are reportedly on the ground with their special operations, so are the british. the italians have really committed to helping this government, to help train that new libyan military >> r 1 ose 0 : well, it is a complicated story but an important one for us to fovment fred wehrey, thank you very much. appreciate it. >> thank you. >> woodruff: stay with us. coming up on the newshour: the senate races most effected by who's at the top of the ticket; a region in recovery-- the repercussions of mount st. helens, 36 years later; and the lesser-known side of mark twain-- a stand-up comedian. but first, medical care for u.s. military veterans. two years ago, the department of veteran affairs was overtaken by news reports of poor care for the people it's supposed to serve. wait times to see doctors in some places stretched for months, and some v.a. staff covered it up. a number of reforms followed but now those very reforms are in the spotlight. hari sreenivasan has the story. >> a few minutes ago, secretary shinseki offered me his own resignation. with considerable regret, i accepted. >> sreenivasan: the resignation of v.a. secretary eric shinseki, a decorated, former chief of staff, was one of the most visible signs of a crisis that gripped the v.a. in 2014. it started when doctor sam foote, at the phoenix v.a. blew the whistle on the incredibly- long waiting times for veterans to see doctors at his facility. dr. foote told reporters, including gwen ifill, that the hospital's director manipulated the data to make the waits seem much shorter. >> we were doing pretty well until about 2010, and then the demand just ramped up. and rather than own up to the problem, the v.a. decided to cover it up, because there's no incentive for washington to get good numbers. >> sreenivasan: the v.a. inspector general found that phoenix-area veterans seeking care had to wait an average of 115 days-- almost four months-- for a first appointment. and 1,700 veterans were kept off any official waiting list, and were at risk of being lost or forgotten. other investigations found this type of problem existed at many v.a. hospitals throughout the united states. the president and congress vowed to fix the problem. one of the reforms authorized veterans to go to doctors in private practice if they couldn't get timely appointments at the v.a. but according to recent reports the wait times with the new system are just as long as they were before the reforms were implemented. and with me now to tell us about this new system plagued by old problems is quil lawrence. he covers veteran issues at npr. quil, this was supposed to be the fix. why is the fix broken? >> well, it goes back to that moment of scandal, there was a sefns urgency in congress. and some political rivals, jeff miller republican of florida and bernie sanders of vermont who is now much better known, from opposite ends of the spectrum came together with this plan to get all of these veterans, this back log waiting for care, to see private doctors. it was supposed to be a simple plan with a card, they could go and use. it seemed at first they would just be able to go into a private clinic and weren't this card and get care. but what was given to the va was a law to set up a whole new network, to get care for anyone who had been waiting 30 days. or was 40 miles away from a va clinic. and congress gave the va just 90 days to set this up. they tried to-- they first thought they might be able to do it themselves. decided they needed to go outside to get some private contractors to set up the system more quickly. and only two of the 57 companies they approached to try and do this were willing to give it a shot. the result has been really just an extra layer of bureaucracy that a lot of veterans tell me makes them wait even more than they were waiting before or just as much. wait times haven't gone down. >> sreenivasan: give me some examples you, and you and others have been talking about them being impacted by this. what happens to them and what is hair process like. >> npr is cooperating with member stations around the country. we have been looking into this for several months. i went down to pennsylvania and talked to bishop smalls, a navy veteran who has some terrible chronic pain issues in his legs. he had been trying to get physical therapy for awhile. when are you in this much pain it can sometimes cause depression. he hasn't been able to find work. around he thought the program would be perfect for him. he had been told it would take him more than 30 days to get an appointment at his local va. and after calling the third party companies, calling and calling and calling, the first place they sent him to informed him they were no longer participating in the choice program. this sun before the problems they have had. they can't seem to set up a network. and the network participates are getting paid so slowly, that some of them drop out. they just don't want to participate in the vet's choice program any more. >> sreenivasan: so the doctors aren't getting paid and perhaps that is a reflection on how quickly they are calling these folks back is. >> right. we spoke to another veteran in montana, tony lapinski, an air force veteran, and he was also just waiting around. he had a growth in his spine. he didn't know what it was. he thought it might be nothing. thought it could be the sort of thing a doctor would tell him later, well, this is cancer. if you had come to us sooner, we could have done something. when he finally was able to see a specialist, he found out that the va wasn't paying these people on time. and this has caused another problem with this program, is that some veterans when the providers don't get paid by the va, these providers try and bill the veterans. and hundreds of vets have had their credit ratings slashed because the va isn't paying the doctors who gave them care. >> sreenivasan: so what happens now? clearly trying to set up an entire health care network in 90 days, we should maybe learn from that. but what are memrs of congress trying to do? are there any new efforts to try to fix the fix? >> yeah, there are efforts under way to consolidate all the va's many programs for care outside va system. those are happening now. there have been a goal to get them done by memorial i da. i'm now hearing that sun likely. but there is also a lot of resentment in congress among people who drafted this that the va hasn't moved quickly enough on it. that it's now a year and a half in. and it is still not really delivering on what it promised to be. >> what about the veterans themselves? it seems that getting care, after what they have been through, and the delay after delay after delay, maybe contributes to even more problems of depression or perhaps worse health care outcomes because they couldn't see someone soon enough. >> sure. i should say i have spoken to some vets who use this program and had no problem with it but we've also just heard loads of complications. we talked to a veteran in san diego, a navy veteran named amanda woods. she said she was in so much pain from complications related to a tumor this january, that she was near suicidal. she tried to get an appointment through veteran's choice and the best they could do was give her an appointment two months out. we found that some veterans are trying the choice program and it takes so long, that thousands and thousands of them are returning to the va and just saying well, the appointment i get here would be faster. >> sreenivasan: overall wait times at the va are worse than they were when they program started. they say that's because of a huge influx of demand. but the assessments, the outside assessments of this program is it just hasn't moved the needle. >> sreenivasan: quil lawrence of npr, thanks so much. >> thank you. #r >> woodruff: of the three remaining candidates, only democrat bernie sanders was on the campaign trail today. this, the day after two democratic primaries: in kentucky, an official winner has still not been called, but hillary clinton holds a razor- thin lead over sanders. the vermont senator did win in oregon, but he remains the underdog for the party's nomination. the drawn-out primary battle is sparking tensions between sanders himself and party leaders, an issue he tackled last night during a stop outside los angeles: >> the democratic party is going to have to make a very, very profound and important decision. it can do the right thing, and open its doors, and welcome into the party, people who are prepared to fight for real economic and social change. i say to the leadership of the democratic party, open the doors, let the people in! >> woodruff: presumptive republican nominee donald trump, who coasted to victory in oregon's g.o.p. primary, met today with a former secretary of state henry kissinger. that, on top of the names his campaign unveiled today, of potential supreme court nominees in a potential trump presidency. he has also discussed what's behind his sharp tone on the trail. that was in an interview that aired last night, with fox's megyn kelly. >> i've been saying during this whole campaign that i'm a counter-puncher, you understand that. i'm responding. now, i then respond at times, maybe ten, i don't know, i mean, i respond pretty strongly. but in just about all cases, i've been responding to what they did to me. so it's not a one-way street. >> woodruff: and while the contest for president gets most of the attention, it could also have a ripple effect down the ballot. there are 34 u.s. senate seats up for grabs this election cycle, and of those, seven are considered a "toss up." these include the open consts in nevada and florida, where harry reid and marco rubio have announced they're not seeking re-election. to discuss all this, we're joined by stuart rothenberg, founding editor and publisher of "the rothenberg and gonzales political report;" and david wasserman, he's house editor for the "cook political report." we welcome boft you to the program, stuart, let me start with you. remind us why it matters who has a majority in the congress. we spend so much time on the presidential race. >> we spent so much time covering the race and talking about the race. but when you get down to it, after the election is over, the president is going to have to work with the house and the senate if they're going to deal with any fundamental issues. and they've had a hard time on big issues like tax reform, immigration and the like because the congress and the president haven't worked well. so knowing what is going on in senate races and the house, who is getting elected, i think it tells us something about what is going to happen after the november elections in the next congress. >> woodruff: let's talk about both the house and the senate and start with the senate. i'm going to focus on that with you. we listed what, 34 seats are up. >> right. >> woodruff: this year. seven considered tossups, is there some rhyme or reason to those that are most vulnerable? where are they? >> most of seats are republican seats. remember, 24 of the 34 seats are republican seats. these are republican seats, republicans who were elected six years ago, in 2010, if you remember that election, judy, and i know you do. that was the first obama mid term. voters were angry, frustrated. many republicans thought the president had gone too far too fast. and they wanted to send a message. send az message to barack obama by electing republicans in the senate. they did that in many swing states. >> woodruff: so now they are coming bang. >> winning wisconsin, pennsylvania, ohio, these are all swing states. and given the polarization of the country and polarization in these states, it's not surprising when you get swing states. you get competitive elections. >> woodruff: so dave wasserman, give us a big picture of the house of representatives. you have 435 seats in the house. how many of those are considered vulnerable up for grabs? >> well, today we only consider 36 districts to be competitive. and really democrats need 30 to get a majority. right now republicans have 247 to 188 seat advantage. that is the largest majority they have had since 1928, since herbert hoover was elected. the question is whether democrats can really tie republican incumbents and can the das to dan ald-- donald trump thasm is easier said than done. last fall we were talking about both party leaders suggesting major seats in jeopardy for republicans if trump were the nominee. now both parties are taking a more cautious approach because after all trump doesn't have a coherent ideology. he doesn't have a voting rohr. a lot of democrats are saying now they might have had an easier time running against cruz because at least they have that play book written. >> woodruff: so in other words it's not as clear that he is the automatic detriment for some of these republicans, is that what you are saying? >> that's true. i think democrats will pick up seats. they could pick up somewhere between 10 and 15 seats if the elections were held next tuesday. those next 15 to 20 feets get really hard for democrats to pick up because not only have fielting deadlines passed for a majority of districts, so democrats didn't scrt opportunity to convince candidates to get into some of these races against republicans. also republicans have a huge advantage in terms of having drawn the lines in 2010. so there really aren't a vast number of targets. if there are any targets for democrats it's districts with high latino shares, where you could see a spike in turnout against trump or districts with high levels of well educated voters where trump could perform unusually poorly for a republican. >> woodruff: let's pick up on that. >> i believe there are 26 it districts where there are a republican congressman who just get carried by barack obama. there five on the other hand, five democrats hitting in romney districts. so the republicans have much greater risk. there are more republicans sitting in what are ostensibly sway democratic districts but not enough so the democrats have an easy chance of picking up 30 seats. >> woodruff: back to the senate for a moment, stu, is there a pattern here? we know that each member is running on his or her own record. >> they are going to try to run on their own record. >> woodruff: but how much of it is a trump affect? >> i think since so many are swing states. illinois is heavily democratic. mark kirk got elected because of unusual circumstances so he say little different but wisconsin, pennsylvania, florida, new hampshire and ohio are all classified as presidential swing states. and they have in most cases republican incumbents, florida is an open seevmentd but the question is request the republican incumbents here run their own races or are they going to be defined by donald trump. and if you are kelley in new hampshire or rob portland in ohio, your problem self ree morning that you get up, a reporter is going to shove a microphone in your face and ask you what do you think about what donald trump said yesterday. >> woodruff: for house members, dave wasserman, it say little different, isn't it? they are not as high profile. obviously on a statewide basis, it's more in their district but they can get swept up in this as well. >> that's true. it may make it even more difficult for them. they have seen less time to communicate from voters and separate from the top of the ticket in an environment where the presidential race is getting all the attention. and it is the main event. and so for example, the new hampshire, in the senate race, she said she will support the nominee of the republican party but she won't endorse. that is kind of a move of ju jit sue that is difficult for a lot of voters to understand. a lot are dealing with the same kind of con undrum. >> woodruff: there was some, a number of people were scratching their heads over what the difference between support and endorsed. i want to ask you both about a scowp elf developments today to the bernie sanders really getting into what seems like a difficult disagreement with the democratic national committee over how soon he should pull back, get out. he is saying every voter needs to vote. is this something that doesn't have a consequence. >> as a democratic race continues, bernie sanders seems to be rasm the-- ratcheting up the rhetoric. and to the extent that he does that, it risks some democratic core groups turning out in november, since he is frankly unlikely to bed nominee. and what is 4eus biggest groups, 18 to 29 year oldsk young voters are they going to turn out for hillary clinton, and if they don't turn out for her, they are not going to be able to vote for the democratic candidates in swing states. >> woodruff: dave wasserman, the other story we reported is donald trump announcing his potential supreme court nominees, po tengszly if he is elected president. i don't think we've ever seen anything like this. is this the kind of thing that could have legs as a story, as an impact on voters? >> this seems to be the year of gimmicks. ted cruz announcing, before wrapping up the nomination, donald trump announcing supreme court picks before even overtaking or coming loss close to clinton in the national polls. mofs voters will be more concerned about the temperment, the readiness of the candidates. who will bring about the best kind of change that they want in november or the most change rather than particular people that they want to see on the supreme court. most people understand donald trump will come nature a conservative, hillary clinton a liberal justice. >> woodruff: gentlemen, it is great to you have both. dave wasserman, stu rothenberg, thank you very much. >> thanks, judy. #r >> woodruff: mount st. helens is washington state is one of the most well-monitored volcanoes on the planet, and with good reason-- it's still active. and more than three decades to the day after it launched a stunning and destructive display of lava and ash, it continues to transform a region and its ecology. even now, scientists are still learning about the aftermath, and how some life is returning from the ashes. science correspondent miles o'brien has the story, part of our new weekly series about exploring the "leading edge" of science. >> reporter: 36 years after its spectacular, deadly eruption, mount st. helens still rumbles and bears scars from that earth- shattering day. but hike down the slopes away from that jagged crater just a little, and you'll see mother nature hard at work. and, there's a good chance you'll bump into a team of scientists led by john bishop. he is an evolutionary biologist at washington state university vancouver. >> the goal of our research is to understand how plant and animal communities reform after a catastrophic disturbance. >> reporter: bishop is one of a select group of researchers studying this rebound from a volcanic eruption. back in 1980, mount st. helens had given scientists all kinds of clues that a big disturbance was brewing. two months before it blew, the volcano was venting huge amounts of steam and there was a series of earthquakes. even with all those ominous signs, the eruption was larger than anyone predicted. it happened at 8:32 a.m. on the morning of may 18, 1980-- an earthquake caused the north face of the mountain to collapse. >> after that, it uncorked an explosion that was directed horizontally, and leveled the forest to 13 miles out from the volcano. >> reporter: the eruption column of volcanic ash and gas rose to 80,000 feet, while a tsunami of 1,800 degree gas and rock raced down the valley at 450 miles an hour-- a so-called "pyroclastic flow." >> anything biological that was remaining after the landslide would've been completely vaporized. it was just a barren landscape, gray and pumice colored. >> reporter: it killed every living thing in a 230 square mile area. what was left was akin to a moonscape. 57 people died. some remains were never recovered. bishop and his team have had a front row seat as nature got busy bringing this place back to life. they wanted to know where it begins and how it takes root. here, it started with these purple flowers; alpine lupine were the first plants to return. for many years, they were pretty much the only game in town. but as they went through their life cycles over several seasons, they created soil from the volcanic ash. and that made it possible for woody plants, like the sitka willow to find a home. they are how a forest gets started, but it hasn't been easy for them. >> one of the things we've realized about these willows is that, they're not getting big. and that's important because they create habitat for birds and mammals. we've learned that these landscapes are characterized by extreme instability. >> reporter: in a recovering ecosystem like this one, where just a few species have managed to regain a toehold, even seemingly insignificant pests can play an outsized role in how the landscape bounces back. these weevils are an invasive species, with a particular taste for sitka willow. >> any stem larger than about one centimeter is usually destroyed by this weevil, and the effect of it is to keep these plants small, not let them form the architecture that's needed for bird and mammal habitat. >> reporter: but bishop says it's important to remember we are still early on in what will be a very long game. he says the plants and insects will battle it out over time, and eventually the ecosystem will become more diverse, more stable, and this will be a forest again. >> when i'm out there working on the pumice plain, you know, one moment i'll look around and i'll be stunned by the amount of vegetation and the number of birds that are present. but then the next moment i step back and i think, there is hardly anything here. we're centuries away from having an old growth forest, replacing the old growth forest that was there. >> reporter: mount st. helens is the perfect place to test an important question in ecology-- life does go on, but how? john bishop will keep looking for the answer here, unless mount st. helens awakens and reboots the landscape once again. i'm miles o'brien, reporting for the pbs newshour. >> woodruff: finally tonight, "hunger is the handmaid of genius." that's mark twain. in this latest addition to the newshour bookshelf, jeffrey brown explores the long, complicated tale of twain's own life, and how one of america's greatest writers, was also a pioneering stand-up comic. >> brown: in 1894, at age 59, mark twain was the highest-paid writer in the land, a national celebrity, author of "the adventures of tom sawyer," "huckleberry finn," "the prince and the pauper," and a slew of other books that are still required reading more than 100 years after his death. but he was also nearly broke, after several investments and business projects went bust. a new book captures what happened next-- "chasing the last laugh: mark twain's raucous and redemptive round-the-world comedy tour" it tells of his travels and performances across the american west, to australia and new zealand, india and south africa. i joined author richard zacks recently at one of twain's favorite washington d.c. haunts, the historic willard hotel and its round robin bar. >> brown: so we know mark twain had a lot of talent. but what probably many of us, and i didn't know, was one of his greatest talents was losing money. >> extraordinary, a genius at it. he lost money with the page type setter, he lost money setting up his own publishing company. and he lost enough money to go deeply in debt at the point in his career when he thought he was just going to retire as america's greatest writer. >> brown: already very famous, a lot so much behind him. ready to glide out. >> he was greedy, he wanted to get paid a higher royalty. and he was convinced that if he owned the publishing house, he could pay himself 90% royalties. the trouble was that he so mismanaged the publishing house, that there was no left to pay him any royalties. >> brown: so this was a point in his life when he really did not want to be performing anymore. that was behind him. >> he wanted, kind of, be a literary giant. and he said, not wanting to go on stage, he said, "once an audience has seen you stand on your head, they expect you to remain in that position." and he felt that it was humiliating. >> brown: he went out big time, right? the biggest ever. >> it's the first time a standup comic has ever done around the world tour. and he didn't know how he would be received because he was a little on the tail end of his career. so here he is going out there, and he is going to australia, new zealand, in india, and his performing style is so dangerous. he would put a hand like this, stand there, dressed in an evening suit, and talk in a very low key, very, very slowly. >> brown: so this is not stand up comedy the way we think of it with joke after joke after joke. this is story telling, so what made it work? i mean, why was he so good at it? >> the delivery is almost unique. i think he was a once in a millennium humorist. i love his early, i mean he wrote about the boatman, the arab boatman charging so much to cross the sea of galilee. that they understood why jesus learned to walk on water. >> brown: okay, that's a little quick, that's a good joke. he would spin out these stories for a long time. >> excellent point! he did 7-15 minute stories, he did 90 minutes total. he had three full performances memorized, three 90 minutes, i'm telling you audience was gasping for air. he's building and building with drama and you don't see it coming. >> brown: so, australia, new zealand, india, south africa. give me one place or example that grabbed you in your research that you loved. >> it's just so easy to pick. india. he fell in love with india. he adored the glamour, the exoticness and he rode elephants in india. and he got, what i would consider the greatest perk in the history of celebrities perks, they set aside 33 miles of the darjeeling himalayan railroad, that he could use as personal roller coaster. i mean, who gets that? >> brown: this is the very steep, through the mountains >> yeah, 7,000 foot elevation. four places were so steep, they had to reverse the train and zig-zag it. and twain goes down in his family with a hand car, with an open canvass seats, no seat belts we were told about, and the only thing to stop them was a handbreak. and some of the drops were over 1,000 feet. he said it was arousing, tingling pleasure, best day of the entire trip. >> brown: you know, one of the pleasures of this story is that while it's begun out of poverty itself, almost, or trying to fight it off, he lives really high life. only the best hotels, the cruise ships, the train trip, >> he is such a contradiction, which is why i think he is so unbelievably funny. he wanted to be a man of the people, but he wanted to live the most aristocratic life. he wanted to be the funniest man but he wanted to be a literary giant. he travels around the world to pay off his debts, but because his wife was an heiress, he thought they should stay at the absolute best hotel in every city. and he burned up maybe a quarter of his potential profits on hotel and first class steamer tickets. >> brown: and he wanted to be a great writer, not some kind of clown act. did he feel like he got there? >> i think he had mixed feelings about it-- because he is always referred to as the great humorist. it really irritated him that he wasn't accepted and the interesting thing is that he choice as his best book to his dying day was "joan of ark." he would sometimes said "huckleberry finn" to certain audiences, but he more often in the final years said "joan of ark." and livy had no doubt, his wife was convinced "joan of ark" was his greatest book. >> brown: you had to spend several years, and what came out about his personality, his life? what did you come to like most? >> what i came to like most was the unbelievable humor. the ability to rephrase things, few of us can stand prosperity. another man's i mean. but twain lived at those fringes, and he had an inner battle between his inner river boat gambler and his inner joan of ark. and it was fascinating. >> brown: the end of that trip is where that famous line came from that we remember, right? "the reports of my death are greatly exaggerated." >> i love this story, so twain is living in seclusion in london and he is writing his book and the "new york herald" reports he is dying in poverty, the great humorist. and the rival paper, the "new york journal" sends a telegram and says, if twain dying in london in poverty send 500 words. if twain has died in poverty send 1,000. so the reporter naiïvely hands the telegraph to twain, to twain's servant, who carries it down the stairs, and he pulls out a note that says, "reports of my illness grew out of my cousin's illness. reports of my death was an exaggeration. the report was an exaggeration as changed over time." and it has changed over time, to "reports of my death are greatly exaggerated." and one more point, he was more irritated by the reports of the poverty than he was of the death. the death he can handle, everyone dies, but that he had died in poverty was why he was furious. >> brown: the book is "chasing the last laugh." richard zacks, thank you. >> thank you. >> woodruff: on the newshour online right now, when you turn 65, you become eligible for medicare. but if you're still working and are covered by your employer's health insurance, should you get medicare? on our "making sense" page, our medicare expert offers some advice. all that and more is on our web site, www.pbs.org/newshour. tune in later tonight on pbs the debut of a new series "genius by stephen hawking" takes a cast of everyday volunteers on a journey to tackle some of humanity's most enduring problems. and on pbs's charlie rose: angus king, the independent senator from maine, weighs in on the presidential race. and that's the newshour for tonight. on thursday, want to spend your retirement changing the world? "making sense" of harvard's university's fellowship for seniors. i'm judy woodruff. join us online, and again here tomorrow evening. for all of us at the pbs newshour, thank you and good night. >> major funding for the pbs newshour has been provided by: >> bnsf railway. >> lincoln financial-- committed to helping you take charge of your financial future. >> fathom travel, offering cruises to cuba and the dominican republic. travel deep. >> genentech. >> supporting social entrepreneurs and their solutions to the world's most pressing problems-- skollfoundation.org. >> supported by the rockefeller foundation. promoting the wellbeing of humanity around the world, by building resilience and inclusive economies. more at www.rockefellerfoundation.org. >> and with the ongoing support of these institutions and individuals. >> this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. captioning sponsored by newshour productions, llc captioned by media access group at wgbh access.wgbh.org this is nightly business report with tyler mathisen and sue herera. rising odds, the federal reserve is thinking seriously about increasing interest rates next month, but there's one thing they want to see first. housi housing, with starter homes in short supply what's stopping builders from building more of them. organic foods is growing fast but farmers haven't kept pace. why that's about to change if one business has its way. good evening and welcome. i'm sue herera. tyler mathisen is on assignment tonight. june was