(AP Photo/Jessica Hill, File)

Hillary Rodham Clinton and her rivals for the Democratic presidential nomination are thinking about whether American students should be able to graduate from college without owing a dime.

"What voters are looking for is someone to be a champion for everyday people. For young people, that's debt-free college," Clinton's campaign manager, Robby Mook, said on Wednesday. The campaign later said that Mook was simply describing the concerns that motivate young voters, not advocating for a policy, and that Clinton would lay out more detailed proposals on higher education in the near future.

As Sahil Kapur reports for Bloomberg, Mook's statement follows months of work by activists and endorsements of the idea by Sen. Bernie Sanders, the independent from Vermont who is challenging Clinton, and former Maryland Gov. Martin O'Malley, who many expect will join the race.

Their plan would help a relatively small group of people, though. At The Week, Ryan Cooper notes that helping college students is really about helping the upper middle class:

The most important fact about higher education is that only a minority of people go to college. Though the proportion of people with a college degree has been rising for a long time, as of 2012, only about 40 percent of the population held a two-year degree or higher. That 40 percent, of course, overwhelmingly overlaps with the upper 40 percent of America's income distribution.

The upshot here is that free college will inexorably tend to benefit the rich disproportionately, both because wealthy people are vastly more likely to go to college, and because a college degree sharply increases their earning potential.

For every student to graduate without debt, the federal government would have to help them pay their tuition one way or another, and that would be costly. That money might be better used to help people who really need it, because most graduates with student loans are basically doing OK. In any case, they're usually better off than the majority of Americans who lack a degree.

Correction: This item has been changed to make clear that Robby Mook's comments Wednesday were not meant to convey Hillary Rodham Clinton's support for any particular policy on the cost of going to college. The campaign has not yet taken a position on the issue.

Welcome to Wonkbook. To subscribe by e-mail, click here. Send comments, criticism or ideas to Wonkbook at Washpost dot com. Follow Wonkblog on Twitter and Facebook.

What's in Wonkbook: 1) Court rules against NSA 2) Long reads, including Gawande on wasteful health care 3) The feds will investigate how Baltimore's police department uses force, and more

Chart of the day: The average global concentration of atmospheric carbon dioxide surpassed 400 parts per million for the first time in March. "It’s the level that climate scientists have identified as the beginning of the danger zone," one climatologist explained. Angela Fritz in The Washington Post.

1. Top story: NSA program ruled illegal

An appellate program has ruled against the National Security Agency on phone metadata. "In a blistering 97-page opinion, a unanimous three-judge panel of the U.S. Court of Appeals for the 2nd Circuit overturned a lower court and determined that the government had stretched the meaning of the statute to enable 'sweeping surveillance' of Americans’ data in 'staggering' volumes. ... The NSA’s mass collection of phone records for counterterrorism purposes — launched after the Sept. 11, 2001, terrorist attacks — was revealed by former agency contractor Edward Snowden in June 2013. The revelation sparked outrage but also steadfast assertions by the Obama administration that the program was authorized by statute and deemed legal by a series of federal surveillance court judges. But the judicial rulings had taken place in secret until the Snowden leaks forced disclosure of once-classified opinions." Ellen Nakashima in The Washington Post.

Section 215, which was the focus of this decision, expires June 1. "The ruling puts new pressure on Senator Mitch McConnell of Kentucky, the majority leader, to make serious changes to the Patriot Act, which he has so far aggressively defended against any alteration, even as recently as Thursday on the Senate floor. Mr. McConnell has pressed to maintain the N.S.A.’s existing program against bipartisan efforts to scale it back, and has proposed simply extending the statute by the June 1 deadline. But the court’s ruling calls into question whether that statute can still be used to issue new orders to phone companies requiring them to turn over their customers’ records. Thursday’s ruling is the first time a higher-level court in the regular judicial system has reviewed the N.S.A. phone records program. It did not come with any injunction ordering the program to cease, and it is not clear that anything else will happen in the judicial system before Congress has to make a decision about the expiring law." Charlie Savage and Jonathan Weisman in The New York Times.

The ruling set Republican presidential contenders at odds. "Minutes after the court’s announcement, Sen. Rand Paul of Kentucky, who has challenged the constitutionality of the program, called the ruling a 'monumental decision for all lovers of liberty' and urged the U.S. Supreme Court to strike down the spying program. ... That stance puts him at sharp odds with Sen. Marco Rubio of Florida... Likely Republican contender and former Florida Gov. Jeb Bush last month said President Barack Obama’s support for using big metadata was the 'best part' of the administration. ... [Sen. Ted Cruz (R-Tex.)] said the ruling 'ends the NSA’s unfettered data collection program once and for all, while at the same time preserving the government’s ability to obtain information to track down terrorists when it has sufficient justification and support for doing so.' " Lesley Clark for McClatchy.

Congress had no idea what the NSA was doing, the court found. "Perhaps the most important message the unanimous decision sends is a simple one: Congress could not have intended to approve a program whose true scope almost no one outside the National Security Agency fully comprehended — that is, until Edward Snowden leaked its details to the world. ... It is particularly galling that the government cannot even point to evidence that any terrorist attack has been thwarted by the collection of all this data. But even if it could, the panel said, 'we would expect such a momentous decision to be preceded by substantial debate, and expressed in unmistakable language.' For too long that debate did not happen, nor could it, since the intelligence court operated in near-total secrecy. Now, thanks to Mr. Snowden (who still lives in exile in Russia), the debate is well underway, and not a moment too soon," writes the editorial board of The New York Times.

2. Top long reads

Exploitation of workers is routine in nail salons. "Once an indulgence reserved for special occasions, manicures have become a grooming staple for women across the economic spectrum. There are now more than 17,000 nail salons in the United States, according to census data. The number of salons in New York City alone has more than tripled over a decade and a half to nearly 2,000 in 2012. But largely overlooked is the rampant exploitation of those who toil in the industry. The New York Times interviewed more than 150 nail salon workers and owners, in four languages, and found that a vast majority of workers are paid below minimum wage; sometimes they are not even paid. Workers endure all manner of humiliation, including having their tips docked as punishment for minor transgressions, constant video monitoring by owners, even physical abuse. Employers are rarely punished for labor and other violations." Investigative series. Sarah Maslin Nir in The New York Times.

With construction comes a debate over the shadows cast by new urban buildings. "With its $95 million penthouse, 432 Park Avenue [in Manhattan] tops out just shy of 1,400 feet. It will remain the tallest residential building in the Western Hemisphere until the Nordstrom Tower — high-end shopping below, lavish apartments above — goes up four blocks away. Between them are a few more audacious developments, all part of a race for ever-taller towers to distinguish luxury living in an increasingly crowded city. Together, these towers, and new additions in neighborhoods undergoing a building boom from San Francisco to Toronto to even low-rise D.C., have revived a long-simmering urban tension: between light and growth, between the benefits of city living and its cost in shadows. ... They change the feel of space and the value of property in ways that are hard to define. They’re a stark reminder that the new growth needed in healthy cities can come at the expense of people already living there. And in some ways, shadows even turn light into another medium of inequality — a resource that can be bought by the wealthy, eclipsed from the poor." Emily Badger in The Washington Post.

Patients regularly receive expensive treatments that are completely useless. "In 2010, the Institute of Medicine issued a report stating that waste accounted for thirty per cent of health-care spending, or some seven hundred and fifty billion dollars a year, which was more than our nation’s entire budget for K-12 education. The report found that higher prices, administrative expenses, and fraud accounted for almost half of this waste. Bigger than any of those, however, was the amount spent on unnecessary health-care services. Now a far more detailed study confirmed that such waste was pervasive. ... Virtually every family in the country, the research indicates, has been subject to overtesting and overtreatment in one form or another. The costs appear to take thousands of dollars out of the paychecks of every household each year. Researchers have come to refer to financial as well as physical “toxicities” of inappropriate care—including reduced spending on food, clothing, education, and shelter. Millions of people are receiving drugs that aren’t helping them, operations that aren’t going to make them better, and scans and tests that do nothing beneficial for them, and often cause harm." Atul Gawande in The New Yorker.

3. In case you missed it

The Justice Department will investigate the use of force by Baltimore police. "Attorney General Loretta E. Lynch has decided to launch a federal investigation into whether the Baltimore Police Department has engaged in a 'pattern or practice' of excessive force. Lynch’s announcement about the Justice Department’s probe — the latest in a string of municipalities that are being investigated by the federal government for civil rights violations — could come as early as Friday, according to two law enforcement officials." Sari Horwitz in The Washington Post.

Cameron and the Tories pull out a victory. "Prime Minister David Cameron and his Conservative Party won a surprisingly solid victory in the British general election on Thursday, with nearly complete results Friday morning showing the party close to an overall majority in Parliament. The result defied pre-election polls that suggested a tight race between the Conservatives and the opposition Labour Party. It returns Mr. Cameron to 10 Downing Street for a second term, possibly with enough seats in the House of Commons that he will not have to rely on support from smaller parties to enact his agenda." Steven Erlanger and Stephen Castle in The New York Times.

Scottish separatists were also winners. "Just eight months after ­losing a referendum to declare Scotland’s independence from the United Kingdom, the Scottish National Party (SNP) was poised Thursday night to sweep the bulk of the region’s 59 parliamentary seats. ... Now the issue is how the SNP would operate as the third-largest party in Parliament in a government led by the Tories, given sharply different views on Scottish independence and Britain’s membership in the European Union." Dan Balz and Griffe Witte in The Washington Post.

The Senate has passed a bill on the Iran negotiations. "Both sides will get their wish in legislation that cleared the Senate on Thursday, a classic compromise that enhances Congress' prerogatives without seriously challenging the president's constitutional authority to conduct foreign policy. Under the measure, which now goes to the House, Congress will have time to vote to reject any deal before sanctions are lifted. And Obama retains the right to veto lawmakers' disapproval. Unless Democrats defect the administration in droves, his veto will stand and the agreement will go into effect." David Espo for the Associated Press.

Policymakers will be watching Friday's employment report. "Analysts surveyed by The Wall Street Journal expect the Labor Department to report that employers increased payrolls by 228,000 in April after a small increase of 126,000 the month before. They also expect the jobless rate for April to tick down to 5.4% from 5.5%. If the report meets those expectations, Fed officials are likely to regain some confidence that the economy is getting back on track. This, in turn, would leave them on a path toward raising short-term interest rates later this year. Right now, a September rate increase looks like the most likely outcome for the Fed. Variations above or below consensus in the jobs numbers Friday would likely shift expectations around that date." Jon Hilsenrath in The Wall Street Journal.

Number of the day: 1.9 percent. That's the decline in U.S. productivity in the first quarter of this year. "The numbers confirm a longer-run trend of slowing productivity that is alarming policy makers and complicating Federal Reserve decision-making. ... Some economists say these weak numbers are jarring given the inventiveness being displayed in sectors such as software, medicine, and advanced manufacturing, and the rapid advance of robotics." Sam Fleming in The Financial Times.

Does Hillary Clinton have a problem with male voters? "Quinnipiac University's new poll of Iowa Democrats has Hillary Clinton up by a mile, mile-and-a-half -- but with Bernie Sanders surging to 15 percent. ... Support for Clinton among men dropped -- and is now below 50 percent. One state, a long way out. Clinton will win Iowa, almost certainly. But something may be going on here that should make Clinton's team raise an eyebrow." Philip Bump in The Washington Post.