The simple fact is that there aren’t enough states like Iowa and New Hampshire—where whites are a majority of voters and the large bulk of the Democratic Party—to give Sanders the kinds of wins he needs to capture the nomination, or even make the fight as competitive as it was at the beginning of February. Despite his fundraising prowess and enthusiastic supporters, his strength is running low.

That doesn’t mean Sanders has been unsuccessful or that he should leave the race. An able competitor, Sanders has forced Clinton to sharpen her message and work for the nomination. And he’s pulled her somewhat to the left, prompting her to embrace a public option for the Affordable Care Act and move in line with the base on the Trans-Pacific Partnership and the Keystone XL pipeline. Which is to say that, if Sanders’ goal is to make the Democratic Party more ideological, he should stay in the game, pressuring Clinton and forcing further commitments to his agenda.

Indeed, Sanders’ campaign can serve as a base for other left-wing efforts to shape the Democratic Party. Now is the time to endorse down-ballot candidates, pressure less liberal Democrats, build a policy agenda, and lay a foundation for future candidates. In short, now is the time for Bernie Sanders to construct a Sanders wing of the Democratic Party that will push and advocate for social democracy.