On Monday, Vermont senator Bernie Sanders unveiled an audacious upgrade to his longstanding campaign promise to make public college free: His platform now includes the cancelation of all outstanding student debt in the United States, too. The announcement comes two months after fellow White House hopeful Elizabeth Warren, who also supports tuition-free public college, called for the forgiveness of up to $50,000 in student debt for anyone making less than six figures each year. In a race increasingly defined by the candidates' detailed policies, things are starting to heat up.

The primary differences between Warren's and Sanders's proposals relate to the inclusion (or exclusion) of a means test. For borrowers whose annual incomes exceed $100,000, Warren would gradually phase out the benefit by providing one less dollar in debt relief for every three dollars in earnings. (So, for example, a recent graduate making $130,000 would receive a $40,000 reduction to their balance.) This formula means anyone whose household income exceeds $250,000—the top 5 percent of earners—would be ineligible to receive anything. According to her campaign, the proposal would affect 42 million borrowers, 95 percent of whom would have their balances reduced, and 75 percent of whom would watch their balances disappear altogether.

Sanders, whose embrace of a free-college platform in the 2016 Democratic primary helped propel the idea into the mainstream, has a plan that is both more expansive and more expensive. It would cancel the student debt of everyone who has it—45 million Americans—regardless of their annual income or accumulated wealth. In a press conference on Monday, he excoriated "the absurdity of sentencing an entire generation, the millennial generation, to a lifetime of debt for the crime of doing the right thing"—"going out and getting a higher education." Minnesota congresswoman Ilhan Omar, New York congresswoman Alexandria Ocasio-Cortez, and Washington congresswoman Pramila Jayapal, among others, will co-sponsor a version of Sanders's proposal in the House.

Both Warren and Sanders have similar ideas about who should pay for their respective schemes: rich people. Warren estimates a ten-year price tag of $1.25 trillion, which she would cover with a 2 percent "ultra-millionaire tax" on families whose net worth exceeds $50 million. Sanders says his plan would cost $2.2 trillion over the next decade, which he says he'd pay with a "speculation tax": fractions-of-a-penny levies on transactions involving stocks, bonds, and other Wall Street investment products. (He stumped for a similar idea back in 2016, too.)

Some opponents of tuition-free public college and universal student debt forgiveness argue that the policies are "regressive," in that they use taxpayer dollars to confer the same benefit on wealthy and less wealthy taxpayers alike. The concern is that failing to discriminate among potential recipients actually exacerbates the effects of inequality, since an investment banker with six figures' worth of debt cannot make the same compelling argument for public assistance as, say, a social worker burdened by the same. The structure of Warren's proposal reflects this sentiment: It gives more to those who need help more, and less to those who need it less. Even so, one analysis from the center-left Brookings Institution predicted that under Warren's plan, the resultant decreases in monthly payments would be concentrated in the upper-middle class.

By eliminating means-testing altogether, Sanders's idea is even more susceptible to such criticism. But its design is a politically savvy choice that trades on the appeal of time-honored programs like Medicare and Social Security. Because it extends debt forgiveness on the same terms to everyone, it avoids potential hand-wringing over who does or does not "deserve" the state's benevolence; compare the skepticism with which Americans have viewed welfare programs that target only the poor, for example, with Americans' strong support for publicly funded K-12 education. And universal benefits are likely to become universally popular ones. As Sanders spokesperson Keane Bhatt told Vox, “There is something to be said about simple, intelligible policies that build broad constituencies.”

The race's two most progressive entrants, who rolled out dueling proposals to tax the super-rich earlier this year, are offering primary voters another chance to compare and contrast strategies for fixing the root causes of economic inequality. And with the first set of Democratic debates just days away, the competing plans may force every contender on the debate stage to take a position on student debt relief, as well.