augusta. those are some of the stories we're covering 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. >> lincoln financial-- committed to helping you take charge of your life and become you're own chief life officer. >> and the william and flora hewlett foundation, helping people build immeasurably better lives. >> and with the ongoing support of these institutions and... >> this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. >> ifill: the white house stepped up efforts today to win over congress on the iran nuclear deal, as lawmakers returned from their holiday recess. secretary of state john kerry briefed house members this afternoon, and plans to brief senators tomorrow. he's trying to head off a bill that could bar president obama from lifting some of the u.s. sanctions on iran. >> we hope congress will listen carefully and ask the question that it wants, but also give us the space and the time to be able to complete a very difficult task which has high stakes for our country. it involves major national security, major issues of potential conflict versus peaceful resolution. >> ifill: meanwhile, russia announced it's clearing the way to send missile defense systems to iran. foreign minister sergei lavrov said the framework nuclear agreement means there's no reason to withhold the weapons. fighting in ukraine between government troops and russian- backed rebels is escalating again, after more than a month of relative peace. european observers report new violence around the rebel stronghold of donetsk, including nearly 1,200 explosions on sunday alone. more than 6,000 people have died since the clashes first broke out more than a year ago. the italian coast guard rescued 144 migrants off libya today. they're the latest in a new surge of people trying to cross the mediterranean sea. many of the rescued were taken to sicily. officials say they were on dozens of rickety boats that sailed from north africa in recent weeks, as weather conditions improved. in barcelona today, the european union's foreign policy chief expressed concern. >> the official numbers of the people rescued at sea over the weekend by the, in this case, the italian authorities, were 5,600 people over the weekend. and this tells us of an emergency that we have to tackle together for the sake of saving lives. >> ifill: italian officials estimate more than 170,000 migrants from africa and the middle east reached italy by sea last year. another 3,500 drowned making the attempt. in nigeria, the number of child refugees doubled in the past year, to nearly 800,000. the united nations childrens fund, unicef, says they've been forced from their homes by boko haram, the islamist militant group. the report says children have been sexually abused and forced to marry militants. others have been turned into fighters, or even human bombs. back in this country, a white, reserve sheriff's deputy in tulsa, oklahoma with charged with manslaughter today for killing a black suspect. on video of the april 2 incident, he says he meant to pull his stun gun, not his revolver. lawyers for the victim, eric harris, said today, they don't believe that. >> the spin on mr. bates getting confused at the last second is false. you'll see mr. bates has a yellow taser strapped to his chest. he has the revolver in his right hand. he was standing over eric harris when shoots him in back. >> ifill: and in south carolina released audio of the white policeman who fatally shot a black man in the back. michael slager fired eight times as walter scott ran from him. he's now charged with murder. the audio is from the dashboard camera in slager's cruiser. he's heard telling a supervisor: "i don't understand why he took off like that. i don't understand why he'd run." four former blackwater security guards were sentenced today for killing 14 iraqi civilians in baghdad, in 2007. one was given life in prison. the others got 30 years each. the four guarded state department officials in baghdad, and said they opened fire after being shot at. prosecutors called it an unprovoked ambush. on wall street, stocks drifted lower to start the week. the dow jones industrial average lost 80 points to close below 18000. the nasdaq fell seven points, and the s&p 500 slipped nine. and, the nobel prize-winning german novelist guenter grass died today. he challenged germans to face their nazi past, but later, had to admit his own. jon snow of independent television news has this report on his life and work. >> reporter: one of the most venerated but controversial literary figures, guenter grass, in his work and in his life, always chose to take a stand on moral, political and social issues. for many, he gave a voice to the generation that came of age in nazi germany, driving them to confront the horrors of their history. his first novel was "the tin drum." it's partly based on his own beginnings. he grew up in the free city of danzig, now godansk. it is a story that takes place in the first half of the 20th century, under the rise of the nazis, through the life of a boy who refuses to grow up. critics applauded grass's magical realist style. and 40 years later, it won him the nobel prize for literature, hailed as one of the enduring works of the 20th century. he was praised for embracing the victims, losers and lies that people wanted to forget because they had once believed in them. >> reporter: he was a seasoned left wing campaigner, speechwriter for chancellor willy brandt in the early 70's. but in 2006, he shocked the world when, in his memoir, he admitted that at the very end of the war he had himself been a member of the elite waffen ss. he was accused of hypocrisy and moral suicide. but defended the fact that it had taken him 60 years to make his revelation. >> ( translated ): i've only now been able to reveal it. and whoever wants to judge me may judge me. >> reporter: he continued to both cause offense and win support. in 2012, a poem he wrote branded israel a threat to the world, earning him a ban on traveling there. the author salmon rushdie here at grass's 70th birthday celebration, said today on twitter, that he was a true giant, inspiration and friend. germany's culture council described him as more than a writer, a seismograph for society. >> ifill: guenter grass was 87 years old. still to come on the newshour: the race for the white house shifts into a new gear. iraq appeals for additional resources and firepower in the fight against islamic state militants. scientists work to develop environmentally friendly cement substitutes. tax day is coming, as the i.r.s. struggles under budget cuts, and for accountability. plus, the 21-year-old who broke records and triumphed at the masters. >> ifill: every week, a new face arrives on the 2016 presidential scene. tonight, it's republican senator marco rubio of florida . yesterday, it was, to no one's surprise, former secretary of state hillary clinton. tonight she's scheduled to arrive in iowa. newshour political editor lisa desjardins kicks off politics monday with a look at the accelerated race. >> i'm hitting the road to earn your vote. it's your time. and i hope you'll join me on this journey. >> reporter: hillary clinton, arguably the nation's most famous woman, is on a journey of reintroduction, tweeting pictures en route to iowa. after a quarter century in the public eye, as a candidate's wife, a policy-driven first lady, a u.s. senator, a presidential candidate, and a globe-trotting secretary of state... >> i'm back! >> reporter: ...she is running for president again, hoping to clear the democratic field by shifting the focus from her history, to the voters' future. >> i'm getting ready to do something too-- i'm running for president. americans have fought their way back from tough economic times. >> reporter: this time, clinton, 67, hopes voters will see hillary the grandmother and potential glass ceiling breaker. sunday's announcement video highlighted young people, a gay couple, latino brothers and, most of all, women. at the same time, republicans lining up to run hope to make the campaign about clinton herself-- especially about her controversies. >> we must do better than the obama/clinton foreign policy that has damaged relationships with our allies and emboldened our enemies. >> she doesn't have a track record of leadership or trustworthiness. she's not the woman for the white house. >> hillary clinton represents the failed policies of the past. does america want a third obama term or are we ready for strong conservative leadership to make america great again? >> reporter: as clinton made her way to iowa today, yet another republican critic joined the increasingly crowded race: freshman senator marco rubio. rubio, a 43-year-old cuban- american who served as speaker of the florida house before coming to washington in 2012, is positioning himself to outpace another likely major candidate from the sunshine state, former governor jeb bush. he would be the youngest candidate in the race so far. but his most famous moment on the national stage came when he delivered the 2013 republican response to the state of the union address. >> on foreign policy, america continues to be indispensable to the goal of global liberty, prosperity and safeguarding human rights. the world is a better place when america is the strongest nation on earth. >> reporter: rubio becomes the third republican to officially announce his candidacy. he joins two other senators-- ted cruz of texas, and rand paul of kentucky. bush and wisconsin governor scott walker are expected to jump in shortly. while the republicans compete to position themselves as the antidote to the incumbent president, clinton is tied to the man who defeated her in 2008. >> i think she would make an excellent president. >> reporter: whether the president's endorsement helps or hurts may prove a key question in the race. for the pbs newshour i'm lisa desjardins in washington. >> ifill: now, joining me for analysis this politics monday: amy walter of the "cook political report," and tamra keith of npr. she's in iowa tonight, waiting on hillary clinton. -- tamra, let's start by talking about secretary clinton, mrs. clinton. what is the goal for her roll out, this interesting web-driven roll out? >> she's now on van tour of america making her way out. she is probably not driving. the secret service is most likely driving. she says she hasn't driven since 1996. what she's trying to do is say, hey, i'm like the rest of you. i'm relatable. i'm trying hard, i'm going to work for every single vote. her campaign is aiming to go small at first. small events intimate settings. no big arenas no big, cheering rounds, but just sort of hillary clinton unplugged, at least initially, much like her listening tour in new york when she first ran for senate there. >> ifill: amy let's talk about what you think she was trying to accomplish. it wasn't as warm and fuzzy as the 2008 video but still very much about her and other people. >> she wants to make sure and very clear that she doesn't see this as her legacy or birthright or something she's going to get handed. her campaign talks about earning the vote, how she's going to work to meet people: it's telling that the first part of the video was others talking about her lives. we didn't hear anything about her life. >> we know about it. lot about it and we're going to hear a different perspective on her life. her campaign tells you she's a person nobody knows. i have a hard time believing that to be true but they're going to try reimagine hillary clinton. >> ifill: let's talk about how the republicans will imagine her. we saw an explosion of web responses this week. rand paul announced he was running for president. let's take late ad of posted after hillary clinton announced. >> hillary clinton represents the worst of the washington machine -- arrogance, power, corruption, coverup conflicts of interest and failure of leadership with tragic consequences. the washington machine is destroying the american treatment. >> ifill: tam -- the american dream. >> ifill: that's what rand paul and a lot of republicans are trying to say is there's an old hillary clinton we want to remind you about. >> absolutely. i think there are many american voters who have a visceral reaction to hillary clinton that goes back to the '90s and what rand paul, what they're doing, what they're trying to remind everyone of is, you know, this is the -- remember the old hillary clinton? remember the one maybe you didn't like as much? they're trying to remind voters about hillary clinton and rand paul has promised he's going to run against her and he's out of the gate running against her. >> i think it's also interesting in the piece beforehand looking at jeb bush and ted cruz and some of the other republican candidates, it's clear they want to make this race about foreign policy. secretary of state hillary clinton came into this election -- comes into this election actually as the best prepared on foreign foreign policy of anybody in the field and she did not mention it at all. there's something to be said about the fact that she also stands in the shadow of a president and his handling of foreign policy which right now is as a majority of americans know, say they think he's not doing a particularly good job. she also has some of her own controversies as secretary of state. the economy, meanwhile, doing a little better and she's hoping to keep the focus on that. >> ifill: sitting here east coast time, marco rubio, freshman senator from florida, announced he's running. he's been saying watch what's coming. let's hear what he said a few moments ago. >> at the turn of the 19th 19th century, a generation of americans harnessed the power of the industrial age and transformed this country into the leading economy in the world and the 20th century became the american century. well, now the time has come for our generation to lead the way towards a new american century. >> ifill: pamela, a lot of code words -- our generation, new youth -- he was clearly pointing out how different she from everyone else in the race. >> he's not just talking about hillary clinton, he's talking about jeb bush his political mentor. he's not coming out and say no more boomer presidents, but that seems to be what he's implying. his other message is marco rubio is telling his story as an american story. the prepared remarks towards the end, he says, you know, the son of a bartender and a maid could make it in america and he wants people to be able to live the american dream again. so in some ways similar to president obama making his personal story an american story and selling himself that way. >> ifill: is it agreed hillary clinton duels not want to make this biographical yet, that's what marco rubio is trading on at this point. >> right. he's young charismatic the parents of immigrant -- >> child. -- sorry, child of immigrant. he's non-white first-term senate. i think that's going to be one of the challenges for marco rubio going forward within his party and out, they're saying we had a charismatic person, young coming in and talking about change do, we really want to take another chance on a young person. he's trying to show how different he is from barack obama. >> ifill: hillary clinton was spotted in ohio in her van. everyone's waited with baited breath. is there other activity on the ground in iowa beyond hillary clinton's spirited arrival? >> former virginia senator jim wag and other governors have been at several events. they have been going to events that are will be happening. they haven't been throwing their own events. they're saying a real test will be how many people show up when martin o'malley or jim webb have a stand-alone event. so it's not clear how well they're performing whether they're getting traction. obviously, hillary clinton coming to town is going to change the dynamic significantly. >> ifill: amy, how much of this getting out front now -- we bring it up every week -- is about money and trying to position yourself with the generation marco rubio talked about today? >> i think that's important. it's ted cruz and rand paul that announced, not jeb bush, he's taking his time announcing, but we're in an era where we find individual fundraising is not tend all it used to be. the fact that ted cruz has a super pac set up apart from his campaign pledging $31 million says that, you know, when you get into the race and how much money you will raise before the summer is not always going to be -- is not as definitive as it once was. >> ifill: next, we have -- who's going to be next. ben carson i think will be coming up soon enough in detroit in early may but we'll probably hear about a couple of others. >> ifill: we'll talk about it next week on politics monday. tamra, i would go to a coffee shop chipotle if you're looking for president clinton. >> gas station. >> ifill: gas station. thank you. you can follow the race online and find guides for each to have the covenants pbs.org/newshour. >> ifill: over the last two days, u.s. war planes conducted more than a dozen strikes against the islamic state in iraq. on the ground, iraqi forces launched a counter attack against the group's strongholds in anbar province. while the fight rages, iraqi prime minister haider al-abadi heads to washington. he'll meet with president obama tomorrow, to ask for weapons and an increase in air support. for the latest on all this, i spoke earlier today with newshour special correspondent jane arraf, who's in baghdad. hi jane, welcome. haider al-abadi is on his way to washington. what is is he coming here looking for? >> h he's essentially looking for more of pretty much everything, more air strikes, more intelligence support, more weapons and possibly some help with financing those weapons. it's a rather long list. it's his first trip to the u.s. as prime minister. he's going to tell president obama essentially that this isn't just an iraqi fight, it is a fight against the i.s.i.s. for the entire world and they need more help particularly more heavy weapons and more ammunition pretty much more of everything. >> ifill: is there any way to quantify is success so far of the anti-i.s.i.s. air strikes not only in tikrit but now apparently anbar? >> they've done wonders certainly in places where i.s.i.s. had been deeply entrenched. in anbar, it's a very complicated dynamic. what we've seen in tikrit is shia militias leading the fight, leading the iraqi military. it worked in tikrit. it won't work in anbar where tribal leaders and the majority sunni province made clear as there are limits to what they will put up. with we spoke this evening with the governor of anbar and she said -- he said they're desperate for help. he says there are no red lines that they will accept help but sid there are militias and then militias. and the militias as you know have been an intrinsic part of the fight. the iraqi government turned to them when it said it didn't have a choice but it's at the cost of alleged human rights abuses and a deeing of the sectarian divide. so essentially the u.s. is wading into a very complicated conflict in anbar. the air strikes have helped so far but there are more air strikes that can deepton divide and air strikes don't arrive without proper intelligence reports. >> ifill: are there any successes the iraqi government forces can claim credit for absent u.s. support? >> it's a really tricky one. everything here is so interwoven. so there are some successes on the ground, primarily in terms of the counterterrorism forces, the special forces, the elite forces the u.s. had a large role in training, unlike the iraqi military that collapsed when the i.s.i.s. fighters came in. basically, they can't do it alone. they're very thinly stretched and took a lot of casualties in tikrit. it's a really interesting and complicated and troubled coalition. it's not just the u.s.-led coalition on that side, it is a coalition on the ground with more than 30 groups seem lig working together but sometimes working at odds. a lot of those are major iranian-backed militias but some are splinter groups and some are fighting with each other. so it's a very complicated dynamic and potentially very dangerous dynamic going forward as the iraqi military tries to push forward into anbar and then eventually into mosul. >> ifill: today i gather the iraqi government was boasting of their captives the i.s.i.s. captives they have in custody. >> yes, they showed us 12 of them. these were men who were in yellow or orange jumpsuits who were paraded in plastic handcuffs, blindfolded. they shuffled them into a room and then we were told that these were men who were captured in raids just to the south and in some cases west to have baghdad. they also displayed bomb-making equipment, the interior ministry burks they said these capitalist accused i.s.i.s. members had actually been found guilty and were waiting for sentencing. being found guilty they said was the result of a long investigation, but the process is a secret one. what they really want to do is to show they actually are taking prisoners because having killed what they say amounts to thousands, several thousand fighters, they've come under criticism as well for violating the rules of war. now, we know that the islamic state group doesn't play by the rules of any kind of war or any kind of rules at all but, by the same token, the iraqi government is expected to. so it wanted to show actually it doesn't just kill them, it takes them captive and puts them on trial. of course, we have no way of knowing what these trials are like. >> ifill: jane arraf reporting from baghdad where the war never quite seems to end. thank you. >> thank you, gwen. >> ifill: climate change has prompted scientists to search for new ways to reduce greenhouse gases in all kinds of fields. now, an arizona inventor has discovered an alternative to the unlikely cause of fully 5% of the world's carbon dioxide emissions. special correspondent kathleen mccleery has the story, part of our "breakthroughs" series, on invention and innovation. >> i have here the last surviving bit of an experiment that went wrong. >> reporter: 13 years ago, david stone was a phd student studying environmental chemistry. >> it was the corner lab right up here, and it was behind those windows where i made the discovery. >> reporter: in a lab at the university of arizona in tucson, he hunted for a way to keep iron from rusting and hardening up. >> it got hot, it started to steam, it was, bubbling and spitting. and i thought well that, that didn't work. the next day when i came in and i found it and rescued it from the garbage, i realized this just didn't get hard, it got very hard, glassy hard. >> reporter: stone-- that's his real name-- began to think his discarded rock just might be a substitute for a very common product: cement. it's been called the foundation of modern civilization. portland cement, its generic name, is the glue that allows concrete to harden. and concrete is everywhere-- in highways, bridges, sidewalks, buildings of all sizes, and much more. four billions tons of cement are manufactured each year worldwide-- a half ton for every person on earth. it has a huge carbon footprint. steve regis is senior vice president at calportland, one of the nation's top 10 cement producers. >> this plant if it's making about a million tons a year of cement, will emit roughly 800,000 tons a year of co2 carbon-- greenhouse gases. >> reporter: one reason is the extremely high heat-- about 2,800 degrees fahrenheit-- needed to process the limestone used to make cement. >> in making cement we actually make new minerals. and that uses a lot of heat to cause that chemical reaction to occur. this plant here we're making a million tons a year, just burning in the neighborhood of 20 tons per hour of coal. >> reporter: david stone uses a very different formula: one that doesn't require high heat and recycles materials from other industries. >> the whole process is green. >> reporter: a key ingredient is iron, something he gets from steel mills. >> i discovered that there was this material called steel dust that is not recycled. so it typically goes straight to the landfills. >> reporter: silica is added to the mix, and that comes from ground up glass. finding that wasn't hard either. stone connected with the community college at the tohono o'odham nation, a native american reservation the size of connecticut in southern arizona. there, he met richard pablo a recovering alcoholic looking to turn his life around. pablo knew where to find plenty of used glass. >> just even cleaning the desert and picking up those bottles it kind of gave me an energy, a positive outlook. and then i started thinking about that there's a power behind that. a spirit behind that. even behind that bottle. >> reporter: stone's material called ferrock for the iron, has another environmental plus. >> you can say we are walking on trapped co2. >> reporter: it's a kind of carbon sponge-- stone adds co2-- which makes it harden-- for example into concrete-like paving slabs like these. >> we're stepping down on climate change, this is a carbon negative process that helps trap the greenhouse gas, carbon dioxide. >> reporter: that caught the eye of the environmental protection agency. then e.p.a. administrator lisa jackson came to the reservation and she, too, walked on ferrock. and gave grants of more than $200,000 to build demonstration projects, which employed tribe members like pablo. the prospect of jobs on the reservation has made stone's work attractive, says casey thornbrugh, project director for the land grant office of sustainability at the community college. >> as projects come up such as campus buildings, homes businesses that want to use the material, that's where the jobs come in. >> reporter: stone won a prize for his invention when he was a student. the university of arizona helped him secure a patent and then licensed the technology to him. now, he's formed a company called iron shell. experiments on ferrock's strength are underway at arizona state university in phoenix. >> reporter: professor narayanan neithalath, a civil engineer who develops sustainable materials is running the tests. >> when you talk to anybody about concrete of course the thing they will ask you is what's the strength? it's a much tougher material that will resist cracking. which is much more tougher. actually we found out in our work that this is about 5 times tougher than your conventional portland cement concrete. >> reporter: that strength might help protect a building from an earthquake, a tornado or even a bomb, like the one that brought down the federal building in oklahoma city in 1995. >> what happened in oklahoma city bombing was the explosion demolished all the columns of the building and the building crashed because of the, the weight of it and the columns not being able to support them. but if i have a blast resistant material or something made out of this material, uh what you will have is the, the columns will still become weaker. but it wouldn't collapse just like that and you will save lots of lives and lots of property. >> reporter: at calportland cement, officials say their product has stood the test of time, for more than 100 years. they've won energy star awards from the e.p.a. for 11 years running, for their energy-saving efforts. among the achievements: using alternative fuels such as old tires and recouping some of the co2 emissions. steve regis says his company is always on the lookout for new ways to make cement-- but says ferrock isn't practical for a large scale operation. >> there's a lot of dave's idea, i think it has a good niche market for, for nonstructural block, uh yard art, benches, um, but consider the scale of that compared to uh 200 mile six lane freeway. eight inches thick, or a runaway." >> reporter: stone is well aware he's david to a very big goliath-- but he thinks there will be a market for ferrock eventually. >> so i'm doing my part as best i can to respond so that when the time comes and the world wants to build with new materials, then a carbon neutral or carbon negative i'll be able to step forward and say, yes i have such a material. >> reporter: a material he hopes will one day make a lasting impression. i'm kathleen mccleery for the pbs newshour in tucson, arizona. >> ifill: as tax day approaches, the internal revenue service has an unusual warnings for taxpayers: not everyone who calls the i.r.s. help center will be able to reach an agent, which could result in refund delays this year. the agency blames budget cuts. but critics say the i.r.s. should blame itself. judy woodruff sat down recently for this conversation with the i.r.s. commissioner. >> woodruff: we are joined by the man in charge. commissioner john koskinen of the internal revenue service. welcome to the "newshour". >> thank you. >> woodruff: let me just start this interview by cite ago couple of numbers we have on taxpayers' experiences with the i.r.s. this year. we know last year 70% of the people who tried to get through with a question were successful. this year that's down to fewer than 40%. the average wait time for taxpayers trying to get through to the i.r.s. with questions shot up from 10 minutes last year to 24 minutes this year. hat has -- what has happened? >> the short answer is congress cut our budget and we have fewer people available to answer the phone. >> woodruff: flush that out for us. how much of a budget cut, what does that mean and how many -- >> well, over the last five years, our budget has been cut by $1,000,000,200 million. in december of this year, the last 350 million cut was provided. only nine months left in the year, so difficult chase is. 70% of our budget is personnel. we would not hire new personnel. we also wouldn't hire for as long a period of time as many seasonal workers during the tax season because that's the busiest time to have the the year and we didn't hire a couple thousand temporary employees we normally would hire and those are all decisions we knew would have a negative impact on taxpayer services, warned congress but had no choice. >> woodruff: what has it meant? >> the people who care most about this are the dedicated i.r.s. employees in the call centers and feel great satisfaction when they can help a taxpayer answer a question and they're the ones most concerned we can't provide our taxpayers the service our employees think they have a right to. >> woodruff: i want to quote a congressman, chair of the congressional subcommittee who oversees funding for the agency, andrew cren chao, he said in referring to past problems that the i.r.s. has had, overspending on conferences, misguided, as they put it, scrutiny of organizations seeking tax exempt status. he said "congress has deliberately lowered the funding for the i.r.s. to a level to make them think twice about what they were doing and why." have you and your colleagues been thinking twice? >> twice and more so. the problems that have been cited oftentimes took place two to five years ago. we've solved them all, explained that to congress in great detail. there are some efficiencies when your budget gets cut that you can obtain. but we've saved over the years. when the cuts get se, you have to understand you will do less with less and that's where we are now. >> woodruff: there's another complaint we're hearing from the other side of the capital from the senate, senator orrin hatch who chairs the senate finance committee, he's been raising questions about whether you and the agency are wasting money by paying millions of dollars in bonuses to i.r.s. employees, i think they said 1100 i.r.s. employees, who owe back taxes or have other problems. how do you answer? >> again, when that problem was raised, we investigated it and put in place policies where if you are violating your obligation to pay taxes to the i.r.s., not only are you subject to dismissal but no longer will be eligible for a performance award. >> woodruff: are people today being paid bonuses if they owe back taxes? >> no, we actually monitor everyone in the i.r.s. our compliance rate is over 99%. the i.r.s. had the highest compliance rate of any federal agency or congressional operation. it's a highest compliance rate but we understand we have an obligation. >> woodruff: a new wrinkle has to do with a new healthcare reform law. i could in tax penalties for people who don't have health insurance and there are issues with people trying to reconcile their premium tax credits against their income. we're hearing reports that there are millions of people out there affected by this that many of them are having real problems, they're struggling to figure out their tax issues. is the i.r.s. handling this? >> we spent a year trying to explain to tax preparers and taxpayers as much as we could how the act works. we've had a quarter million hits on our web site. a-- from our perspective the filing season is going well. 90% of people used software last year and we work with the developers and taxpayers that they would be provided answers to questions and filing would be straightforward and we monitor calls to see if there are questions coming in that we need to answer where the answers aren't available and, thus far, from our perspective, things have gone well. i would emphasize over 75% of people check a box and say they have coverage. so for the vast majority of people filing the aca act has not been a problem at all. >> woodruff: but for individuals who may end up not paying the tax they owe either because it's a penalty or for some reason they don't get the taxes they're due, what is the i.r.s.'s position when it comes to enforcing this? are you going after people? are you going to provide leniency because you're strapped for personnel or what? >> thus far our experience is, and we have a couple of days to go, that the people who are affected in the reconciliations 40 or 50% of them are getting an increase in refund because they underestimated the advanced premium they were eligible for and the other half that are getting a smallerrer fund basically are getting smaller refunds. we don't see a large or significant number of people who are actually being put in a position of owing taxes they can't play. we made it clear the treasure department policy, if you can't pay you should file but there will be no penalties. you will be absolved of penalty but you have to file. >> woodruff: another thing to ask you about is the question that is raised by the challenges the i.r.s. is dealing with right now in terms of personnel and that is auditing. we know that the percentage of returns the i.r.s. audit last year dropped to the lowest it had been in a decade, less than half or about half over1%. is this -- half of 1%. is this an invitation of people toll avoid taxes, particularly wealthy people who have all sorts of complicated forms to fill out? how much are you concerned about your ability to audit as many people as you think need to be audit? >> i am concerned. people said when you underfund us and we have 5,000 less auditors and criminal investigators it is a tax cut for tax cheats. everyone who pay taxes wants to feel it's fair. if they feel some people are cheating and getting away wit that undercuts the voluntary compliance system. i would note there are still 1 million individual audits this year, when it you are the one, it may take us longer to find you but there will be tax and penalties on what you didn't pay. while we are concerned about it in the long run, we are telling taxpayers you still have a good chance of getting caught and if you get caught consciously trying to avoid taxes, you won't be happy. >> woodruff: so the message is don't relax because you're having a difficulty in dealing with number of people. >> woodruff: that's right. the vast majority of americans take the obligation seriously are compliant do the best they can and we want to help taxpayers to figure out how much they owe and how to pay it. >> woodruff: only a couple more days to go. john koskinen, commissioner of the i.r.s., thank you very much. >> my pleasure. >> ifill: it was a history- making weekend for golf in augusta, georgia that recaptured the television spotlight. 21-year-old jordan spieth became the second-youngest golfer to win the masters, only a few months older than tiger woods was when he picked up his first green jacket back in 1997. jeffrey brown has a look at spieth's accomplishment. >> brown: jordan spieth led the tournament from start to finish, the first time that's happened in 39 years, as he beat back challenges from some of the game's biggest names. along the way, he set several records, for lowest score after 36 holes, and after 54 holes, and for making the most birdies at one masters. after four days, he got to don the traditional green jacket of the master's winner, having tied the 72-hole record of tiger woods. spieth spoke about the moment, immediately afterwards. to put on this jacket is incredible. this feels great. i plan on not taking it off for quite a while. probably sleep in it for the next few nights. but it was a test. there is a reason i have a hairline like this right now and that's because it's stressful what we do on a daily basis and to be able to come to the world's greatest and to come out on top puts a lot of confidence in me -- >> brown: some perspective >> brown: some perspective now from john feinstein, a columnist for the "washington post" and the author of several books about golf, including "a good walk spoiled." he was in augusta this weekend. john, what was the most interesting aspect in the age? the manner of his victory? >> i think it was the manner of his victory. to sleep on the lead as they say in golf for three straight nights -- you lead thursday, friday, saturday, you have to sleep on the lead every night, that's why guys don't go wire to wire only the fifth player in mastersmasters history to do it and then to win and look so calm. other than his hairline he doesn't show stress on the golf course. he was being chased by justin rose, a major champion, phil mickelson three times masters champion. rory mcillroy number one player in the world and he never blinked. there were several blink moments where he might have lost control of the tournament and never did. >> brown: now we are learning about this guy. you followed him for a long time. on the course and off the course we're learning about his personality, family life, all kinds of interesting things. >> he first came to the attention of we golf geeks when he was 16. he was a junior in high school, made the cut and finished 16th 16th as an amateur in a pga event in his hometown in dallas. his whole school was closed on friday so we could go watch him play. he was the oldest of three. his youngest sister ellie who is 14 is autistic. jordan has not only spent a loft time with her as a big brother but volunteered at her school, which is for kids who have learning disabilities. and i think because of that he has a kind of understanding of real life that most superstar young athletes don't. they're anointed, they're spoiled, treated as gods. he doesn't look at life quite that way and a lot of that is lill. >> we've talked about a lot of sports over the years. athletes in different sports mature or become great at different ages, right? what about in golf? tiger woods was one of the phenoms, right? now we're looking at another young man. what's the norm in golf? what does it take to mature into greatness? >> it's interesting because golf has the biggest gap in terms of stardom. phil mickelson was almost 33, walter hagan 21, tiger woods 21, jordan spieth fits into that category. the ones who won at 21, 22 are all in the hall of fame and iconic figures. whether spieth lives up to that, time will tell. but he is on a path to true greatness and i think to being the next great rival for rory mcillroy who emerged as a star and won his first at 21. >> brown: for many years, golf was ruled by tiger woods, much of the focus and he is still much there and over the past few days a lot of focus on whether he's coming back. >> always. >> brown: but there are a lot of new young great players. >> there are. mcilroy won 25, spieth won the masters yesterday, have emerged. tiger woods was a dynasty, the way the yankees or the packers were a dynasty because he dominated the game. we haven't had great rivalry since jack nicholson and tom watson. i think mcilroy and spieth have the potential to be a great rivalry. masters european cup players, both young champions and both comfortable in the spotlight on and off the course. they never seem to really lose their cool even when they fail. rory mcillroy led the masters by four shot just like jordan spieth at age 21 and shot 80 the last day. stood behind the green answered every question never snapped at anybody and said if this is the worst thing that ever happens in my life i'll have a good life. >> talking about sleeping on the lead, that's an example. he slept on it and failed. >> woke up to a night mayor. >> brown: when you talk about them being good in the spotlight, the spotlight was back on, the ratings were up yesterday. >> yes. >> brown: do you think that has a chance to evolve into something bigger for the sport? >> i do. and people have said what happens when tiger woods is no longer playing or no longer a star? i think the answer is based on babe ruth went on -- baseball went on without babe ruth and basketball without michael jordan. some people love dynasties i love rivalries, especially in sports. these two guys again, an american and a european, so they could be competer for the ryder cup some day soon. >> brown: tiger woods, at the end, focus on him? he was there for a bit. >> played well considering he was terrible for the first two tournaments this year. for him, it was an encouraging weekend. he needs to get out and play. >> brown: just to play and get back -- >> not to where he was because he won't. but to get back to where he can contend for a major title. >> brown: john feinstein, thanks as always. >> thanks, jeff. >> ifill: finally tonight, a new documentary provides a unique glimpse into the lives of chicago's homeless students. more than 22,000 children in the chicago public schools are considered homeless. tonight's edition of "independent lens," called "the homestretch," focuses on the high school population, which includes a profile of a young man named anthony. here's a bit of it. e whole night, i'm thinking about breaking out the window: i couldn't sleep because it was so cold. i'll wake up and never go to school in the morning. at school, take up all the emotions and pack thumb down. my teachers thought there was something wrong with me like i'm giving up because there are so many other things i have to think about when i leave here what i'm going to eat when i leave here. >> there you go. have a nice weekend. be careful. it's three on each one. the most important thing i'm trained to do is give them stability here. i do everything that i possibly can to enable them to come to school. my list has grown considerably this year. there you go, sweetheart, have a good day. i have six freshmen eight sophomores, four juniors and eleven seniors. each name represents a story, and it represents a person who is going to be awesome some day. so, that's the list. >> ifill: you can watch the full documentary "the homestretch do not on most pbs stations. >> ifill: finally, to our "newshour shares" of the day, something that caught our eye that might be of interest to you, too. over the weekend, nasa released stunning video taken in february by two go-pros, small wearable cameras. they were attached to astronauts as they completed a space walk. the result: spectacular views of earth, and the intricate construction of the space station itself. the space walk was part of the preparation for the arrival of a crew of new astronauts, including american scott kelly, who will be spending a full year in space. the entire video from the go- pros is over an hour long. you can watch it on our website. pbs.org/newshour. again, the major developments of the day: senator marco rubio of florida declared this evening he's a candidate for the republican presidential nomination. his announcement in miami came a day after democrat hillary clinton made her presidential bid official. and the white house stepped up efforts to win over congress on the iran nuclear deal. secretary of state john kerry briefed house members and warned against "misrepresentations" about the framework agreement. on the newshour online, migrant workers around the globe sent more than $400 billion to their home countries in remittances last year. it's one of the most stable forms of aid to the developing world. so who are the big winners in this equation? read a report, on our home page that's at pbs.org/newshour. tune in later this evening charlie rose looks ahead to 2016 with clinton and rubio now in the race. and that's the newshour for tonight. on tuesday, how a company in portland, oregon is using drinking water to create electricity. i'm gwen ifill. we'll see you on-line and again here tomorrow evening. for all of us here at the pbs newshour, thank you and good night. >> major funding for the pbs newshour has been provided by: >> lincoln financial-- committed to helping you take charge of your life and become you're own chief life officer. >> and by the alfred p. sloan foundation. supporting science, technology and improved economic performance and financial literacy in the 21st century. >> and with the ongoing support of these institutions and... >> 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 request tyler mathisen and sue gerrera. >> investors hope this important group will be a bright spot for the market. >> payday why the heads of some of the country's biggest companies are taking home even bigger paychecks. why most baby boomers are most definitely not ready to . >> good evening, everyone and welcome. it's here. earnings season and the focus is on the banks. the big ones. the ones that can move the market and give us insight into the health of the economy. before the opening bell rings tomorrow we'll hear from jpmorgan. the financials had a rough start to the ye