The biggest winner of the presidential primary process may be someone who lost.

Vermont Sen. Bernie Sanders left Philadelphia this week as the leader of a progressive movement that is tentatively allied with the Democratic Party, which needs him more than he needs it.

Sanders’ campaign priorities are the basis for the party platform, and his focus on economic justice, through a $15 minimum wage, debt-free college and aggressive Wall Street regulations, are now at the heart of nominee Hillary Clinton’s policy agenda.

Sanders could have a big role in the fall campaign, both as a surrogate for Clinton, and as a star attraction in Senate and House campaign events. If he can get young voters to turn out and vote for others the way they turned out and voted for him, his influence in Washington will be substantial. But even if that doesn’t happen, Sanders’ has already changed our politics.

First, he revealed that millions of Americans are ready for progressive change, something that might have gone unnoticed if he had not gotten into the race. Sanders’ unapologetic commitment to New Deal liberalism shows the way for more-cautious politicians who might now try to pursue his ideas.

And he has exploded the myth that refusing to use corporate money through super PACs amounts to unilateral disarmament. Sanders was able to go toe-to-toe with Clinton through state-of-the-art crowdfunding, raising $227 million, mostly in small donations. It’s no longer plausible when a candidate says “I had to take the money.” Proving that this kind of fundraising can work at the highest level could affect who will try to run and how they will campaign for every office, not just the president.

And he has built a political organization that could survive this campaign, advocating policy ideas and recruiting candidates that could have an effect throughout the system.

If not for the strange rise of Donald Trump, Sanders would be seen as the political phenomenon of the year. We saw it in Maine. Last summer he came to Portland and packed the Cross Insurance Arena, delivering his no-frills stump speech, free of biographical anecdotes and “humanizing” touches to an enthusiastic crowd. They turned out again in March, giving him an overwhelming victory in the Democratic caucus.

The Republican primary process left its losers beaten and diminished. But Sanders comes out of the process more formidable than he was when he came in, a little-known, elderly, former socialist from a small state. Sanders and the ideas he championed are going to play a role in this election and beyond, which makes him and his supporters winners.