For Democrats, the one great policy legacy of 2016 was the party’s embrace of free tuition for public colleges and universities. After Bernie Sanders made it a signature policy proposal and proved its political potency (especially with millennials), Hillary Clinton adapted and adopted it when she won the nomination. Over the course of the campaign, the idea evolved from a progressive pipe dream into a concept with massive momentum. This thing was going to happen! But when Donald Trump won and Republicans took control of Congress, a federal free-tuition program became a pipe dream again. The only chance for free college was to start at the state level—in one of the few remaining blue states—and create a model that could spread nationally. Given the popularity of the idea, it’s not surprising that two ambitious Democratic governors–both presidential prospects for 2020—have taken up the call. Both New York’s Andrew Cuomo and Rhode Island’s Gina Raimondo are vying to be the governor who made free college happen—and both their plans are running into resistance from their own party’s lawmakers. Some of the controversy was to be expected: It’s no surprise that fiscal conservatives think it’s another costly social program with uncertain returns. Other legislators and educators worry about how it will affect enrollment at state schools. But for liberals, the legislative battles have exposed a series of tricky policy trade-offs that cut to the heart of a larger national debate: What kind of “progress” should Democrats be fighting for? Should a new social program benefit everyone equally, like Social Security, or help low-income families the most? And how valuable is tuition relief, really, if the state doesn’t help students with other college expenses, like room and board and books? The surface simplicity of the whole idea is one of its great calling cards: Free college. How complicated could that be? The debates in New York and Rhode Island have sometimes been acrimonious and divisive. But that’s far from a bad thing: