Bernie Sanders is making unrealistic promises about his free college plan
What Sanders’s plan, as spelled out in his College for All Act, does is provide federal matching grants to help defray the costs of eliminating tuition for in-state students.
Specifically, he is offering a 2-to-1 federal match for states that do this along with meeting a few other criteria like reducing reliance on adjunct faculty. This is a sufficiently attractive offer that some states would probably go for it. But it’s going to cost a lot of money, and tax-averse Republican governors like Walker pretty clearly aren’t going to do it.