(Associated Press) Days before the first Democratic presidential debates Sen. Bernie Sanders and House progressives rolled out legislation to cancel all student debt going farther than a signature proposal by Sen. Elizabeth Warren as the two jockey for support from the partys liberal base . By canceling all student loans Sanders says the proposal would address an economic burden for 45 million Americans. The key difference is that Warrens plan considers the income of the borrowers canceling $50000 in debt for those earning less than $100000 per year and affecting an estimated 42 million people in the U.S. Questions face both candidates about how to pay for all of that plus their proposals for free tuition at public colleges and universities. But the battling ideas highlight the rivalry between senators who have made fighting economic inequality the cornerstones of their 2020 presidential campaigns.