hillary clinton survive her email troubles and a former president's candid talk of cancer. we'll get the analysis of mark shields and michael gerson. all that and more on tonight's pbs newshour. >> major funding for the pbs newshour has been provided by: ♪ ♪ moving our economy for 160 years. bnsf, the engine that connects us. ♪ >> supporting social entrepreneurs and their solutions to the world's most pressing problems-- skollfoundation.org. >> the ford foundation. working with visionaries on the frontlines of social change worldwide. >> 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: a global financial market sell-off overwhelmed wall street today. investors raced for the exits as chinese stocks crashed again, and oil traded below $40 a barrel at one point. when the closing bell finally sounded, the dow jones industrials had plummeted 530 points to close at 16,460. the nasdaq plunged 170 points and the s&p 500 dropped 65. all three indexes were down more than 3% on the day. and for the week: the dow and the s&p lost nearly 6%, while the nasdaq fell almost 7%. we'll look at what's driving this big drop in just a few minutes. in iraq, a u.s. air strike has killed the islamic state group's second-in-command. the national security council announced today that fadhil ahmad al-hayali died tuesday, north of mosul. a spokesman called him "a primary coordinator for moving large amounts of weapons, explosives, vehicles, and people between iraq and syria." and the u.s. military says isis mortar fragments in northern iraq show traces of mustard gas. they were fired at kurdish fighters this month. north korea went on a war footing today and issued an ultimatum. the north's leader, kim jong un, demanded south korea halt new propaganda broadcasts at the border by tomorrow night, or face a possible attack. at a briefing in pyongyang, a senior north korean officer declared the south deserves "severe punishment." >> ( translated ): their aim is to bring about the collapse of the ideology and system which our people have chosen themselves and which our soldiers protect with their lives, and to deprive us of our power and all areas of our lives. >> woodruff: in turn, south korean troops went to their highest alert status, amid reports of north korean missiles possibly moving to launch positions. at the same time, u.s. officials confirmed a temporary pause in military exercises with south korea, to consult. the exercises have since resumed. in belgium, a moroccan man with an automatic weapon opened fire this evening on a high-speed train, wounding three people. they included an american serviceman, who along with another american, overpowered the gunman. the train was traveling to paris from amsterdam. anti-terror police opened an investigation, but there was no immediate word on a motive. europe's migrant crisis turned violent today along macedonia's border with greece. macedonian security forces used force to drive back thousands of migrants trying to head deeper into the continent. we have a report from juliet bremner of independent television news. >> reporter: from one battleground to another, survivors from syrian's brutal civil war been driven back at the macedonian border. riot police using tear gas and stun grenades force away hundreds of refugees. parents try to shield their frightened children. in the chaos, migrants do their best to tend to one another's wounds. a state of emergency has been declared in the south and the north of the country. around 36,000 arrived in macedonia last month, heading through greece to the border town of gevgaylia. travelling by train to kumanovo, and onwards to serbia and western europe. they don't want to stay in macedonia, they are in transit, but now find themselves trapped. >> there is more coming. they know that we are only crossing. >> reporter: but they are now stuck, sleeping without cover in a country that is not prepared for the influx. >> there are hundreds, babies, including medical needs. most if not all of them stay in the open air. >> reporter: there are calls tonight for an end to these heavy handed tactics, and greece and macedonia to instead offer assistance to desperate people. >> woodruff: more than 160,000 migrants have arrived in greece so far this year, and nearly all head north. president obama declared an emergency in parts of washington state today, as over-stretched crews battle a plague of wildfires. fast-moving flames have scorched more than 160,000 acres in the north-central part of the state alone, and two more small towns were evacuated overnight. officials warned today of worse to come. >> i think probably everybody hears wind howling in the microphones and that is what is truly challenging folks out on the ground. we've got gusts already to 40 miles an hour. we have a tremendous amount of open fire edge at the southern end of all of our fires and the wind is wanting to move it. >> woodruff: three firefighters died this week in the washington state fires and one was critically burned. nationwide, 13 have died this year-- four more than all of last year. and a u.s. federal appeals court today reinstated rules giving the minimum wage and overtime pay to nearly two million home health workers. a lower court had struck down the provisions earlier this year. unions and worker advocacy groups welcomed the outcome. home care companies warned it makes the care too expensive for many families. still to come on the newshour: wall street's big week of losses women warriors making history as army rangers, what the ashley madison hack says about privacy on the internet and much more. let's take a closer look now at wall street's wild day. bringing to a close a long week of jitters. for some answers to what's behind it all, we turn to liz ann sonders, chief investment strategist at charles schwab. liz ann, welcome back to the program. i'm reading, this is the worst week since 2011. what is going on? >> so what may on the surface seem like a bunch of disparate things, they're actually interrelated. weak growth in chierntion data came out today showing part of their economy in contraction. we have the plunge in commodity prices including oil which ties back to the weakness in china. global growth concerns, deflation concerns and deflation is a fairly toxic environment because whether you're a consumer or investor, if prices are continuing to go down, it halts activity. then this is all brought up regarding fed policy and how the federal reserve will react to the global turmoil and we were overdue for a correction. it's been almost four years. they normally happen every year. so this has been a long span of very, very mild equity performance. >> woodruff: well, when you say overdue for a correction, i did read one columnist in the "new york times" today say this is actually, as bad as it seems, he said it's a much needed breather when some markets have been starting to look a little bubbly. that was neil erwin. >> i agree. corrections are healthy, it keeps complacency from becoming pervasive. so it's a cleansing process. whether we're at the end, i'm not sure. the dow is in correction territory, which is down 10% or more. >> woodruff: you mentioned china, how are china's problems with its economy affecting these markets? >> again, they have been huge commodity producers, they caused a huge amount of supply increase force commodities, which set the stage for the plunge we're seeing in commodities. so that's a big part of it. they are the world's second largest economy now. if you take europe as a zone, the eurozone is the second largest to the u.s. but by country it's china. they are a big producer and consumer of things. they have an export market. we and other countries export to them. so a bigger than expected slowdown in china absolutely affects global growth and to some degree our growth. >> woodruff: oil down below $40 a barrel at one point today. what real is that playing? >> for the u.s. economy, 68% triffen by the consumer, it's ultimately a good thing, we are oil consumers. the problem is the hit it causeos the energy sector in particular tends to come immediate and the offsetting benefit to consumers tends to come later. so we're dealing with the immediate hit before the offsetting benefits. >> woodruff: for someone thinking, oh, my goodness, what about my retirement account, a 500-point-plus drop seems dramatic. how concerned should people be? should they take a deep breath and wait to see what happens next week. >> it's always a good idea to take a deep breath and most investors who have acted in panic have not served themselves well. a 10% correction is fairly normal. they happen every year. i think we'll ultimately get through it and don't make rash decisions. we have to look at things in percentage terms. >> woodruff: what would you say about the state of the overall health of the american economy? >> i think the economy is not going to suffer all that much. we are a closed economy to some degree because our economy is two-thirds driven by the u.s. consumer so we tend to be impacted a bit less by things that we see overseas. however we're in a relatively slow growth mode and this won't help that. so i think we stay in the slow growth environment, i think the risk of recession is fairly low. >> woodruff: liz ann sonders, chief investment strategist at charles schwab. good to see you again. >> thanks, judy. you, too. one of the most storied institutions in the u.s. military marked a milestone today. for the first time, two women graduated from the army's elite ranger school. it's a step toward increasing women's role in war fighting. chief foreign affairs correspondent margaret warner has our story. >> reporter: it was an army ranger graduation unlike any other: two women joining 94 men. major general scott miller hailed the survivors of the grueling nine-week course at fort benning, georgia. >> it is all of you who know the challenge of persevering through privation when most humans would just quit. you're leaving victory pond here today with a small piece of cloth on your shoulders. but more importantly, you carry the title of ranger from here on out. >> reporter: this was the first year the army has allowed women to try to qualify or the elite ranger force. 19 began the course, along with about 345 men. the two women who ultimately qualified for the black-and-gold ranger tab: captain kristen griest, a 26- year-old military police officer, who spoke about the challenges yesterday. >> knowing that you have to uphold that legacy every day, you can't really have an off- day, you can't be tired, you need to go the extra mile. >> reporter: and 25-year-old first lieutenant shaye haver, an apache helicopter pilot. >> at each event we succeeded in, we kind of were winning hearts and minds as we went. >> reporter: at yesterday's briefing, they described the exhausting physical and mental trials of the course. >> the mental side of the issue is you come is going to be the most challenging thing you will ever face and exceeding that, my advice is to, once you get to that point, keep going and realize your mind can take a whole lot more than your body can. >> when your squad gets 2,000 rounds of ammo or you realize that you are the weapons squad and you've got two machine guns to carry and you look around and there's only ten of you or so and everybody, all of a sudden all the men really don't care at all that you are female, you're carrying some of that and you feel the exact same way and you are going to help share the load as much as anybody. >> reporter: indeed, some of their male counterparts acknowledged they had their doubts, at the outset. >> i was skeptical if they could handle it physically and then we got to mountains and we were doing a long walk. i was the 320 gunner so i had a lot of weight on me and i was struggling and then i stopped and i asked at a halfway point can anyone take some of this weight, i got a lot of deer in the headlight looks and a lot of people were like i can't take any more weight. shay was the only one to volunteer to take that weight. she took that weight off of me and carried it the last half of that ruck, literally saved me. i probably wouldn't be sitting here right now if it wasn't for shay. >> reporter: for all the praise, captain griest and lieutenant haver are not eligible to actually join the ranger regiment. that still remains closed to women. they'll most likely be assigned support roles instead. but that could change in the next few months, though, as the pentagon finishes reviewing its policy on integrating women into combat units. defense secretary ashton carter indicated his openness to that yesterday at the pentagon. >> the department's policy is that all ground combat positions will be open to women, unless rigorous analysis of factual data shows that the positions must remain closed. on october first, the services will provide a report to the chairman requesting any exception to this policy. and i'll review the services recommendation and make a final determination on that issue by the end of this year. >> reporter: even if women eventually do gain access to most combat roles, the pentagon may allow service leaders to request exemptions. >> woodruff: internet hackers dumped troves of personal information this week stolen from an adultery website, raising new questions about online privacy and the ability of websites to protect it. hari sreenivasan has our look. >> sreenivasan: the hackers said the attack on ashley madison was motivated by the failure of its parent company to deliver on a service that promised to erase users' information for a fee. millions of names, email addresses and partial credit card numbers were released. a public outing that has raised questions about how much privacy any of us enjoy online. joining me to discuss that are: neil richards, a professor of law at washington university in st. louis, where he studies privacy and the internet and julia angwin, who covers privacy for "propublica." her most recent book is called "dragnet nation: a quest for privacy, security and freedom in a world of relentless surveillance." neil, i want to start with you first. we've had the sony pictures hack where thousands of employees of the corporation had their communication and information released, we had the office of personnel management hacked, the 22 million members of the federal government, and celebrity hacks where unsuspecting celebrities had photos from iphones and icloud released. what makes this different? >> it's certainly different because it's nor salacious. it involves sex and betrayal. i think the magnitude of the hack and the sensitivity of the information exposed. i think it's important that we think about these questions because this is a little more juicy in terms of maybe like tabloid news than some of the other hacks but it draws our attention to increasingly what is on enormous problem. >> sreenivasan: information especially on a sensitive site like this sits in a lockbox. to credit this site, this digital set of locks was better than average. is there such a thing as true security? as soon as you type something, is it out there forever? >> sadly, what we're learning is there doesn't seem to be a lot of true security out there in the real world. there may be theoretically real secure stuff. but we've seen a very government sensitive hack. you can consider what's known to be safe, you know, taking files that should have been secured. so seems nothing is impenetrable. but it doesn't have to be that way, i think. there is another world, you can imagine, where the data would be secure, and we have to build that, i think. >> sreenivasan: so, julia, staying with you for a second. is this the reason some of these ephemeral platforms such as snap chat where you're writing with disappearing, inc. or periscope, where your live stream disappears in hours, is that why people are going on this because they don't want to leave a digital trail and the follow-up is if it truly temporary? >> the reason people are going to ephemeral is exactly this. you don't want to have a permanent record of everything you do in life. the world we live in with digital data has led to that world where there is a permanent record for everything. the problem with the ephemeral services is some of them prove to be not efamily rail. the snap chat settled with the f.e.p. because their data wasn't as ephemeral as they said so we're awaiting the true promise of ephemeral data. >> sreenivasan: there's a camp that says if you weren't planning on an affair, you have nothing to hievmentd there is a distinction of privacy and secrecy. privacy is a freedom i have to choose whom to share this information with. >> yeah, it makes for a gad sound byte but not good policy to say we should make everything trance parents and people with nothing to hide have nothing to fear. we all wear clothes, we all lock our houses, we all like passwords on our accounts. i think th the issue here is not whether some people who cheat on their marriages got their come upens. it's a whether we're going to be able to trust the information relationship which characterizes our lives and, yes, dating sites are among them but more importantly social network sites, data brokers, our retirement accounts, all these are information relationships and safe gar bid some levels of security and i think the ashley madison story is a salacious one but an important reminder we need to do a better job of safeguarding sensitive data in our society, so better laws and technical practices and incentives for companies to do this. we have a lot to do. it's important to focus on. this what's at stake is whether we can continue to trust our digital society. >> sreenivasan: is the notion of privacy an antiquated idea or perhaps is it different from generation to generation? >> well, people have been bemoaning the death of privacy in american life for about 130 years, since the late 19t 19th century. privacy is about what information we have control over, about how we get embarrassed, what information restriction can do for us. privacy depends on social norms, it's always changes. in an information society, what we're living in, if we have no privacy rules, we have no information rules, which means we have no rules and, so, rules governing passwords, personal data, search engines, consumer credit reports, they are essential. and i think we are struggling as in other areas of the internet, we are struggling and stumbling into the future half blind it's important to do a better job and do it right. >> sreenivasan: one of the things you looked at in your book is trying to find all the information about you that exists. obviously there are public records out there. we can try to guess what's available but what surprised you? >> i'm trying to find as much as i could about myself. i wasn't that successful. it's worth pointing out there are not things talking about yourda at that. what surprised me is they knew i bought underwear online last week and that file was sold to marketers. i found the government through a confusing slipup with my employer had access to my travel plans as a reporter and who i was planning to see because to have the way we used our system, that database was being sent an entirety of my future travel plans to a government database. so it was really surprising and disturbing stuff in there. >> sreenivasan: julia, you took elaborate measures most of us couldn't take you essentially have alternate identity credit cards, et cetera. are there safe information sharing practices, things we can do on a daily basis to safeguard against this? >> i wish i could give you better set of guidelines but the fact is that it's really hard to avoid these kinds of things. however, that said, some basic precautions are better passwords, really long passwords, so as long as you can make it, 30 to 40 characters. actually, you know, you talk about fake identities like it's a crazy thing, but mix up a couple of email addresses maybe not with your right name for which you register for sites like ashley madison, for instance. >> sreenivasan: thank you both for your time. thank you. >> thank you. >> woodruff: stay with us. coming up on the newshour: how arizona state university is turning its focus to low-income students, plus analysis of the week's news with mark shields and michael gerson. but first: president obama won a significant endorsement today for the iran nuclear agreement as representative jerold nadler of new york announced his support. nadlers' decision followed a personal appeal from the president, who sent him a letter pledging that the u.s. would continue economic pressure on iran and keep military options open. tonight we continue our series of conversations on the agreement as part of our "deal or no deal" series. earlier this week we heard from an israeli scientist who was opposed to the deal. this evening we hear from the former head of israel's intelligence and special operations agency the mossad, ephraim halevy, who is breaking with his country's government and public opinion to support the agreement. mr. halevy, given you disagree with your government, why do you? what makes you see in this agreement that makes you support it? >> i believe this agreement closes the record and blocks the road to iranian nuclear military capabilities for at least a decade, and i believe that the arrangements that have been agreed between the parties are such that give us a credible answer to the iranian military threat at least for a decade if not longer. >> woodruff: you have said that this agreement is historic from the iranian point of view. what did you mean by that? >> up to a couple of years ago, the iranians refused to discuss their nuclear programs on the basis of a negotiation, international negotiations. they said this was their sovereign right to do whatever they wished. they caved in. they have entered have a detailed discussion of their capabilities. they have agreed to an agreement which lists their various facilities in iran. they have agreed to knocking out the first and foremost important element in it, their location in iraq which is a plutogenic producing facility in potential. the core of this particular aspect is going to be destroyed, and that means that there will be no capability of the iranians to ultimately weaponnize whatever they are doing for the purposes of attacking anybody around the world for the next decade. if only for that element alone, i would say this is an agreement worth while accepting. >> woodruff: you said a moment ago you believe this closes the road or route to iran's military capabilities for at least a decade. why are you so confident of that? as you know, israel's prime minister benjamin netanyahu says just the opposite. >> well, i've looked at the details of the agreement. as i said, on the issue of iraq, the plutogenic program, it's clear the core of the reactor is going to be destroyed. where they've had a lot of centrifuges up till now, for those, they will be restricted only to scientific research. there is going to be a clear way of monitoring what is going on there and the facilities there which would allow the produce of natanz and the piping and other elements necessary, to pass on whatever they produce in order to process it into something of a military nature is also going to be removed. so i believe in all three counts, it's clear, in my view, that the capabilities of the iranians to go ahead with their original ideas has been stopped by this agreement. >> woodruff: this is a story that's got an lot of attention in the united states this week and i'm sure in israel as well, the associated press reporting that iran will be able to use its own inspectors. they have a side deal with the international atomic energy agency where irani inspectors will be in charge of looking at the military site, the so-called parchin site. the argument is this is a big loophole in the agreement. how do you see it? >> this is an agreement which is a secret agreement reached between the director general of the i.a.e.a. with the civillism medication of the nonproliferation treaty. the director of this agency is not only a veteran in this field of disarmment, he's been highly regarded and he has impeccable credentials. up till now, israel has respected him and his judgments and i think we should wait and see how the ultimate process of the negotiations he is now conducting with the iranians and the outcome of these negotiations at the end of this year, how he will be satisfied with the arrangements that he's setting up in order to monitor these activities. >> woodruff: ephraim halevy, you've also said clearly that you expect iran to try to cheat on this agreement. why should that be acceptable to the rest of the world? >> it is not acceptable to the rest of the world. that is exactly the whole point of the agreement. whereas when the united states negotiated with the soviet union, the code word which was used by president reagan and secretary schultz was trust and verify. this time, it is mistrust and verify. there is going to be a verification system in place which is second to none and has no precedent, and i believe that if the iranians are going to try and cheat, there will be ways and means of finding this out. i think that the machinery which is going to be put in place which, by the way, will be supported fully by the united states, without which this could not actually be implemented, will not be in place if the agreement is scuttled by congress. >> woodruff: finally, how difficult is it for you to support this agreement when your prime minister, when the majority of israeli public opinion, we're told, opposes it? >> firsfirst of all, there has n no real public debate in israel on this. our equivalent of the united states congress has only discussed it once. i think there is an attempt here to stifle public discussion. i'm not alone in this view. there are others who are thinking likewise, as i am. one of them is the former head of the israeli atomic energy commission, a highly regarded general, a man who led his battalion in 1967 and others like the head of r.&d. of the israeli defense establishment for many years, an air force general. in thin the yom kipur war, we dt want another in reverse. >> woodruff: we thank you tonight. >> good evening. next we wrap up our week-long series: "rethinking college: closing the graduation gap," by visiting with a university president who says the nation's public research universities are failing to meet the needs of low-income students. hari sreenivasan reports. we doubled our number of graduates and went from 9,000 to 20,000 graduates. >> sreenivasan: in the rarefied world of higher education where exclusive schools cater to only the very best students, michael crow is blazing a new path, an anti-elitist. >> it goes back to our admission standards. if you have better than a b average overall, then you're admitted. >> sreenivasan: as the president of arizona state university, crow has dramatically increased the student population to 84,000 students, making it the largest university in america. under crow, the number of low-income students has soared, enrollment of blacks and latinos has doubled, and a.s.u. has accomplished this despite the largest funding cuts from any state legislature in the country. >> the specific freshman experience -- >> sreenivasan: president crow's mantra is a public university should be judged by not who it turns down but who it admits. >> public research universities have become increasingly exclusive and increasingly expensive, believing they needed to emulate the private universities or replicate them. we're saying it's time to innovate and develop a new kind of american university. >> it's all about attitude -- >> sreenivasan: that means breaking down traditional academic departments. the school slashed millions of dollars in administrative cost bys merging academic departments and eliminating support staff. cuts that help fund low-income students and encourage cross disciplinary learning. >> we have 15 or 16 new transdisciplinary schools, school of earth and spacex ploargs, the country's first school of sustainability, a school of social transformation, a school of transborder studies, a new range of ways we approach problems. we've built the building to break down disciplines. we blow up departments. this is called interdisciplinary science building 4. >> sreenivasan: you're getting the pictures from mars and the students are working with nay is a's j.p.l. >> absolutely. christopher is working out data sets. we have the lunar orbiter and people are doing robots and drones and new ways of looking at this. >> sreenivasan: what crow cares about is making the university accessible to low-income families. by expanding the student population from 55,000 to 84,000, the university is able to use money from full-paying students to recruit more who need financial aid. how did you increase access especially to low-income fiewnts. >> talent is a function of your ability, your drive as an individual, not your parents' income. we've found the talent wherever it is. we have a new tool we're about to launch called me 3. >> sreenivasan: crow hopes the me 3 tool will entice high school students from poor communities by giving them a virtual identity. >> this is the me 3 tool. we have a description of what's involved in the major in terms of career outlook, job outlook. >> sreenivasan: frederic corey who oversees the student advisor program says online technologies can get students in the door and keep them there. >> withdrawal is one of the biggest expenses we can face every day. we're looking at this, if i'm doing a sweeping look, i can see what percentage of students in each college are off track. >> sreenivasan: student records are used to predict success. >> you have to take the courses of diagnostic success. if you go off track twice, you have to pick a new major. >> sreenivasan: that's what mapped to roger who switched major from axe chiewrl science to computer engineering after receiving several online alerts. >> i actually got multiple e-mails. they made it clear this might not be right for you because this is a critical course. i admit i was mad at first. >> sometimes it's a process of grieving. you come to terms with the fact that now i need to give up that identity and work with somebody on a new identity. thes>> these are the labs. we need to do more to empower those individuals to be successful and embrace how technology can be our friend. we're trying to find a way to enhance tech -- technology. >> sreenivasan: the push for technology in a larger student body led some to question the quality of learning at a.s.u. >> i don't think that this is a model for a new american university, for those american universities that still like to maintain their prestige. >> sreenivasan: keith law is a professor of merced college in california. he says a.c.u.'s quick expansion and particularly massive online curriculum could damage the university status. >> i think arizona state university is risking slipping into becoming a diploma mill that grants graduation and grants diplomas to students without really guaranteeing them an excellent education and i think that's going to erode the value of their degrees down the road. >> sreenivasan: despite critic, crow sees innovation and online technologies as reshaping the entire university system. >> technology allows both faculty and students to move through courses at a higher rapidity, move through them as you've mastered them. what will that mean for technologies when they say here's a basic concept in psychology. you might be an engineering major and might not take the full psychology course but might take a few courses, plgt 25 credits. >> sreenivasan: the model might be watched closely as american colleges face growing enrollment from less traditional students. in phoenix, hari sreenivasan, pbs "newshour". >> woodruff: donald trump is holding on to his lead in the g.o.p. presidential field. how are the other candidates adjusting? the clinton email saga shows no signs of letting up. and former president jimmy carter and his very public battle with cancer. that brings us to the analysis of shields and gerson. that's syndicated columnist mark shields and "washington post" columnist michael gerson. david brooks is away. ewelcome to you both. >> thank you. >> woodruff: so let's talk about donald trump. as we said, he's holding up in the polls. mark, now that we're a couple of months into this, do we know more about who donald trump is as a candidate, about what he really believes? do we understand better what's going on here? >> i'm not sure, judy, to be very frank about it, how much we know about him. we know what he's publicly emphasizing. i mean, there's a strong sort of howard behl cast, the anchor in "network" played by peter finch who coined the phrase "i'm mad as hell and i'm not going to take this anymore," there is a lot of that to him. he is particularly a republican electorate but electorate general who thinks the country shedded in the wrong direction, that their children's future won't be as bright as their own and the base concerned about the changes in the country, it's racial composition and social mores, acceptance of same-sex marriage, there is an anger and donald trump is addressing that in a flamboyant way that is beholdenned to nobody, seemingly, no interest groups except his own interests. so i'm not sure, there is a lot of perceptions there but i'm not sure there's a core. >> woodruff: do you feel, michael, he has a better handle on what he's trying to say. >> it would seem his first policy initiative, he set out an immigration policy, thin, six pages, not very detailed, but it included changes to the protections of the 14th amendment on birthright citizenship and pass deportations. so this is a person, trump, who, three years ago -- which is not very long ago -- criticized mitt romney's self-deportation plan as m moniacl and mean-spirited, and going to mass deportation. this crosses lines in the republican party, quite serious and i think could damage the republican party for decades to come to be associated with this approach. >> does he explain how he's made that turn? >> there's no explanation. whenever he's caught in changes, he doubles down and his support seems to stay, you know, the same. he is, in a moment, where there is a lot of part zen anger, a lot of candidates, 18 or so republican candidates in a field where he can stand out, and he probably has a ceiling of support. i don't think he's going to get the republican nomination, but he's 20% in the polls and driving the debate on immigration in very dangerous ways. >> woodruff: so, mark, he's making these statements to get a lot of attention, as michael said. he came out this week with his position on immigration. what effect does that have on the other candidates on the republican side, the other 16 of them? >> when the central issue in the campaign is set by the frontrunner, then that is perceived as contributing to that frontrunner being the frontrunner, whether anti-busing with george wallace, whether opposition to the iraq war with barack obama in 2008, there's a natural gravitational pull to say i've got to close the gap between them, a me, too-ism. we've seen that conspicuously in the case of scott walker, the governor of wisconsin who seems to be shadowing trump's philosophical movement. at the same time, judy, let's be blunt about this, there's a mean spiritedness in the electorate he's appealing to. when the cnn poll asks which of all candidates do you agree with, 4-1 margin, the republican voters say donald trump. donald trump, whatever else he is, his position is anti-immigrant overall. it is devastating to the republican party, michael is right, in the long run because asian voters, the fastest growing minority in the country who supported george h. w. bush when he lost badly in '92 voted even more democratic than -- >> 67% of asians -- >> woodruff: hurting in the long run, but in the short run it's helping him with the republican primary voters, right? >> well, there are members, i completely agree, who want to be pale versions of trump, which i think is hurting them and the party. walker has been everywhere on all sides of the birthright citizenship issue and really shown he's not playing in the big leagues, he's not prepared or thoughtful in these areas. but you have rubio and bush who, eventually, one of them, i believe, will emerge as the anti-trump, and make a strong argument ton other side. on immigration. >> on immigration as a whole and his approach to politics. it's going to be very important. what trump is appealing to has more of a feel of european right-wing politics. the national front. highly nationalistic, resentment of foreigners, we have been betrayed by our leaders. there is some deep and disturbing things that are being appealed to here. there is always populous trends. good leaders take those trends and direct them in ways that serve the public good. bad leaders feed those trends to serve themselves, and that's exactly what trump is doing. >> i just point out, judy, 25% in a 17-county field is very impressive. 25% in a three-way race, you're a loser. i agree with michael that both rubio and jeb bush, each is waiting for the other to go first in attacking trump because they want to be the remainder man against donald trump because they don't think donald trump in the final analysis is a majority candidate. what they risk is what trump is doing and saying becomes so odious and offensive that it almost is seen as a moral sur surrender on your part, ultimately, in the general election that you didn't stand up to him and i think that's a real risk anybody runs by not confronting him at this point. >> woodruff: i want to turn us to the other party, to hillary clinton, michael. the email controversy, there was more evidence this week there are real investigations going on, questions about whether these e-mails, if they weren't marked confidential to begin with, they should have been. she's taking this on, had a news conference, talking to reporters about it. do you see any sign she's getting ahead of this issue? is she overwhelmed by it? what do you see? >> no, these events are undermining her main argument this is somehow a political attack. you have the federal judge questioning her conduct this week, the f.b.i., the inspector general of the intelligence community, this is not a partisan deal. this will be determined by real investigations. so i think that's why. and you can see the trouble she's in from the defenses she's made. there's now been three of them. the first one is there were no classified documents, she said that, right. then she said, there was nothing classified at the time that turned out to be untrue. now she said she did not send marked documents, okay. when you take -- when you get top secret clearance and you commit to protecting this material, that's not the standard. you're responsible for negligence, you're responsible for mishandling of material. it's not just the standard, she said. so she's lost control of events. she tried to control things so close by saying i want to control my own information, i want to be able to destroy it. she controlled it in such a way that it attracted attention and is now beyond her control. >> woodruff: how do you see it? >> judy, the "new york times" broke this story six months ago about a private server and quite bluntly we've gone from a time when the investigation appeared to be motivated by the republicans on the hill, with the benghazi story and all the rest of it. now we have a federal judge appointed by bill clinton who's director of the f.b.i., this is going to be around for months and no longer just a partisan witch hunt, it's an official investigation with all the implications that that involves. it's going to color and influence her campaign from here on in. >> woodruff: how do you think she's handling it? >> i think she should have turned everything over right at the outset and said i have nothing to hide including me e-mails about chelsea's wedding. i mean, i don't know what else -- you know, how pleased or displeased i am with the gender of my grandchild when it's announced. you know, there's no up-side for her politically. >> she's had a really terrible launch to her candidacy, there's been a series of questions and things she's been defensive on and there are now democrats thinking in the back of their mind, do we need a plan b. i think that's very real. this has gone from a very small chance to a larger chance where democrats are saying sanders can't carry the ball into the election and there may need to be someone else. there is no one obvious, to be honest. i think the questions have now been raised in a serious way. >> woodruff: there was a report today, mark and michael, that vice president biden was asking technical questions about mount ago campaign, but we'll see. he's indicated he'll make a decision. >> joe biden like every other presidential candidate still dreams about being elected president. it doesn't go away. it is a life-long affliction or inspiration. >> woodruff: we saw this week someone who was president decades ago, former president jimmy carter, i think very gracefully handled the bad news about the medical health news he got in terms of a diagnosis of cancer, melanoma which spread to his brain. mark, this is someone who's been out of the white house for 35, 40 years and, yet, what do you make of this? quite a remarkable news conference yesterday. >> it was, judy. we're in an era that's aggressively secular where church membership is in decline, yet in the past couple of months we've seen two examples of the social value as well as the individual value of religious faith. we saw it at the a.m.e. church, the family survivors of those victims forgiving the killer who was racially motivated, and we see it in jimmy carter who devoted his post presidency to improving the cause of those less fortunate. but showing such grace and courage and humor and faith in the face of this daunting and dooming news. >> woodruff: as somebody who covered the cart white house a long time ago, michael, i was struck by, as mark says, the humor. he said he'd gotten calls from former president bush and president obama and said, of course, i haven't heard from them in a long time. >> right, well, we often get examples of how to live healthfully, successfully, a lot of emphasis on this, but we don't really get examples of how we approach death. this is a really good example. now, it's not imminent in his case. he's seeking treatment. he wants to live longer and may well live longer, but there is a calmness, there is a grace and there is a courage about what he said that's an example of how you deal with the end. and he also dealt with it with gratitude, talking about how grateful he was for his life. that's a real model for all of us. >> woodruff: it is. we saw the medicine he's getting is something that's only been available for the last year or so. with we certainly wish him well. mark shields, michael gerson, great to see you both. thank you. >> thank you. on the newshour online: it's a lost art that has been slowly fading from the urban landscape. glowing neon signs that used to welcome everyone from restaurant goers, hotel guests and gamblers in cities across the world, are being replaced by cheaper and easier to use lights. but a new website tells the story of the iconic signs of downtown hong kong. you can see a photo gallery of some of their brilliant displays, on our home page. that's at pbs.org/newshour. and a reminder about some upcoming programs from our pbs colleagues. gwen ifill is preparing for "washington week," which airs later this evening. here's a preview: >> ifill: an all politics roundtable tonight as we sort through trump-mania, the world of secret email servers and look a bit more closely at the candidates taking advantage of it all to talk about-- of all things-- policy. you wouldn't know it's august. tune in tonight to washington week. judy? >> woodruff: on pbs newshour weekend saturday, our reporting on the economic crisis in puerto rico continues. puerto rico has begun to default on some of its massive debt. the first such failure to pay by an american state since the great depression. >> i think puerto rico is going to be like greece? >> it's happening already. puerto rico is not greece, it's not a foreign >> woodruff: that's tomorrow night on pbs newshour weekend. and we'll be back, right here, on monday as we start a weeklong series: katrina ten years later. that's the newshour for tonight. i'm judy woodruff. have a great weekend. thank you and good night. >> major funding for the pbs newshour has been provided by: >> carnegie corporation of new york. supporting innovations in education, democratic engagement, and the advancement of international peace and security. at carnegie.org. >> and with the ongoing support of these institutions and friends of the newshour. >> 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. stocks routed, the dow dives, tech stocks tank as the blue chip index sheds more than 500 points to cap the worst week on wall street in four years. oil breaks 40. crude prices continue to crater falling briefly below that level. and there's one big problem for that commodity that isn't going away any time soon. and needed repairs, bridges are crumbling but one state found a fast fix to one of its biggest problems. the final part of our week-long series the big fix, tonight on "nightly business report" for friday august 21st. the correction many have been calling for is he