Senator Bernie Sanders, one of the top-tier candidates for the 2020 Democratic presidential nomination, plans to unveil a proposal Monday to cancel all U.S. student loan debt.The College for All Act would cover $1.6 trillion in student debt and would affect 45 million Americans who would save on average about $3,000 a year. The entire plan would come with a price tag of $2.2 billion to the taxpayer, paid for by a 0.5 percent tax on stock trades, a 0.1 percent tax on bonds, and a 0.005 percent tax on derivatives.“In a generation hard hit by the Wall Street crash of 2008, [the plan] forgives all student debt and ends the absurdity of sentencing an entire generation to a lifetime of debt for the ‘crime’ of getting a college education,” the Vermont progressive plans to say in introducing the proposal.Sanders's plan is wider-ranging than that of his 2020 rival, Senator Elizabeth Warren, whose platform includes forgiving $50,000 in student debt for those now earning $100,000 or less, and...