That this man, who has spent most of his life spurning and disparaging the Democratic Party, who is only semi-nominally even a member of the party and who is reviled by some of its biggest names, could be by summer its titular head is a prospect few would believe possible. That is, if they hadn’t seen Trump do something similar in 2016: The ultimate anti-establishment outsider, the almost ridiculous choice in fact becoming the choice. The seriousness of Sanders’ chances can be measured in relation to the apoplexy he’s started to generate among stalwart operatives. Bernie Sanders? “Having him for president of the United States?” longtime Democratic strategist James Carville said when we talked last week. “Are you fucking kidding me?”

Regardless, though, of what happens Tuesday and from here, Sanders, already more than any other 2020 candidate, has shaped the ideological tenor of Democrats’ lumbering primary process—more even than he did in ’16. His “Medicare for All” proposal, the linchpin of his expansive progressive agenda, has served as the policy position around which the other top candidates have defined themselves. Add in the poll numbers for Elizabeth Warren, another left-of-center Democrat angling for giant structural change, and the upper tier of the Democratic field leans more toward Sanders than it does Joe Biden. And he has ensured his stamp will remain on campaigns still to come. By far the most prominent surrogate in the field is Sanders’ Alexandria Ocasio-Cortez, a first-term, just-turned-30 congresswoman from New York City who could be his granddaughter—and whom Sanders supporters and, in particular, his legions of millennials view as proof that all of this is not about just an individual but rather a movement that has altered the contours of liberal politics and is nowhere close to done.

A question hangs here in the wintry New England air.

Is the Democratic Party Bernie Sanders’ party now?