Education reform is the default position of policymakers of both political parties. But even in this favorable environment for “school choice,” there is one policy that many assumed off the table: school vouchers. But despite the reams of research enumerating the policy’s failures, proponents soldier on undeterred. Today, four years after Obama began to wind down the program in Washington D.C., voucher partisans, backed by corporate cash, are hoping to bring their policy to cities like Philadelphia.

School vouchers were first championed by free market zealot Milton Friedman and, as a result, were a favored education policy of Ronald Reagan (along with school prayer). Here’s the idea: the government provides vouchers to parents, who usually must have a low household income, to subsidize the cost of their child’s education at any school of their choice. The vouchers are usually allotted through a lottery system.

Conservative advocates describe vouchers as a sure way to increase student achievement and graduation rates, by allowing low-income parents to move their children to private schools, which are assumed to be better performing. But none of the three cities with the most studied programs, Milwaukee, Cleveland, and Washington D.C., have seen improvements in student achievement.

As a 2011 non-partisan review by the Center on Education Policy of the voucher research literature shows: “these studies have generally found no clear advantage in academic achievement for students attending private schools with vouchers.” Although some research documents higher graduation rates for voucher users, these findings became statistically insignificant when researchers controlled for factors including the education of a child’s parents, household income, number of parents in a household, or religious attendance. “The fact that voucher users have parents who were sufficiently motivated to seek out a voucher suggests that these parents may have a greater tendency than other parents to support and encourage their children to aspire to finish high school and attend college,” the researchers note.

On the campaign trail in 2008, Obama’s campaign made his reservations about vouchers clear. “Throughout his career, he has voted against voucher proposals and voiced concern for siphoning off resources from our public schools,” his campaign stated. “[His education agenda] does not include vouchers, in any shape or form.” Obama was true to his rhetoric on the campaign trail (as most presidential candidates tend to be).

When he became president Obama began to phase out the D.C. voucher program, providing enough money for those currently using it to graduate, but allowing no new applicants. Hardly a doctrine liberal on education policy, President Obama supports the controversial “school choice” ideology and enthusiastically favors charter schools. But he continues to oppose school vouchers. “Private school vouchers are not an effective way to improve student achievement,” reads a 2011 statement from the administration, and Obama’s recent budget cuts all funding to the D.C. voucher program.

But don’t count any idea out, no matter the empirical evidence against it. As journalist and corporate watchdog Zaid Jilani wrote on the blog Think Progress, a “tight-knit group of right-wing millionaires and billionaires, bankers, industrialists, lobby shops, and hardcore ideologues” have consistently championed vouchers (among other controversial reforms), with little regard for actual outcomes. For these voucher proponents, choice is a value in and of itself and private schools are inherently better than their public counterparts.

“The complete privatization of schooling might be desirable, but this objective is politically impossible for the time being,” says Joseph Bast, the president and CEO of the Heartland Institute, a libertarian think tank known for promoting climate change denial and working with tobacco companies. “Vouchers are a type of reform that is possible now, and would put us on the path to further privatization.”

Despite their proven failure and immense public unpopularity, conservatives emboldened by Republican victories in the 2010 midterm elections have brought vouchers back with a vengeance. Corporate front groups have sprouted up across the country to provide ready money for candidates who are willing to consider vouchers. In Pennsylvania, a recent push for vouchers from conservative Republican Governor Tom Corbett was stopped in the Pennsylvania House of Representatives. Now, in this year’s primary elections, multiple anti-voucher candidates are being challenged by opponents flush with cash from groups like Students First, a right-wing corporate front group.

In Philadelphia, challengers backed by pro-voucher money have mounted vigorous campaigns, claiming that their opponents have allowed Philadelphia schools to “fall apart,” misleadingly blaming incumbents for the complex and largely structural issues besetting public education in the city. They do not explain how these problems will be eased by allowing an extremely limited number of students to access a program that doesn’t work.