Sanders’ allegiance has always been to America’s small but passionate democratic, socialist left. He is a veteran of 1960s civil rights, anti-war, labor, and poor people’s campaigns who, unlike many other activists, has never lacked ambition for political office and influence. But until 2016, Sanders always pursued office and power from outside of the two-party system. In one of the quirks of American political culture, the modern mix of artisans, academics, environmentalists, and workers in once rock-ribbed Republican Vermont made it possible for him to become a self-proclaimed socialist mayor of Burlington, then a congressman, then a senator—always as a candidate of progressive third parties or as an independent, one who worked with Democratic allies but was not a Democrat himself.

So unlike most conventional presidential aspirants, Sanders has no deep identification with or debt to the Democratic Party he has now sought to lead. Nor can he expect his turn for that party’s nomination to ever come in the future, especially at age 74. He sensed, as Donald Trump did, that the American public’s frustration with the polarized, gridlocked leadership of both parties created an extraordinary opportunity for outsider candidates in 2016. He seized the moment. Now, having come far but fallen short, even as his counterpart on the right has prevailed, Sanders wants passionately to help defeat Trump in November. But even more so, he wants to employ the political clout he has acquired through his astonishingly potent, insurgent presidential campaign to further movement goals. His aims go well beyond transforming the Democratic Party. He seeks a Democratic socialist “political revolution” in America, making it more like the still-capitalist—but far more regulated—unionized, socially provisioned (and yes, highly taxed) nations of northern Europe. And now is his last, best hope of playing a major role in making that happen.

So he will use every means at his disposal to press hard at the Democratic Convention for Clinton to accept more left-leaning platform positions. He will insist on a prominent speaking role for himself, and he will also seek prime time for speeches by one or two of his most prominent supporters. He will devote his considerable oratorical powers chiefly to firing up his movement activists to carry on their fight, before urging all of his followers, especially the millions of young people he has inspired, to turn out to defeat Trump. With all of the energy and resources he can muster, Sanders will carry both of those messages to key swing states and beyond during the fall. He will campaign particularly hard for candidates who can help the Democrats win the Senate.

The word is that when he then returns to the Senate, Sanders will push for a leadership role on the Committee on Health, Education, Labor, and Pensions, on which he is now a lower-ranked member. If the Democrats capture the Senate, he will ask to be leapfrogged into becoming its chair. From that committee perch he will vigorously champion his signature issues of single-payer health care and free public higher education, while opposing what he sees as anti-labor and anti-environmentalist trade agreements. He will also continue to urge breaking up the big banks and strengthening unions, but under Clinton, his best hopes of success are likely to be on health and education issues. After a long legislative career of, by necessity, doing more position-taking than actual law-making, Sanders will hope to win at least one big, genuine, legislative victory for his movement causes in the time remaining to him—and maybe more. But if he gets even one, he will view his 2016 presidential campaign as a smashing, indeed “yuge,” success. By his lights—the lights of a movement politician, not a conventional politician—he will have every right and reason to do so.

Rogers M. Smith is associate dean for social sciences at the University of Pennsylvania.