You gotta love Bernie Sanders. He came from nowhere, a socialist, of all things, and managed to give Hillary Clinton, the presumptive Democratic nominee for president since Obama assumed office in 2008, a run for her money—literally. He succeeded because he spoke frankly and directly to the leading issues challenging our nation—unacceptable poverty amid unprecedented wealth, and the anxiety of those who can’t find jobs that pay a living wage. He addressed the need to reform campaign spending, halt global warming, advance racial justice, and rein in Wall Street. He had bold ideas and refused to trim his sails. In comparison to Hillary Clinton’s more cautious approach, Bernie was a breath of fresh air for many readers of this magazine, young voters, and progressives of all ages.

But now that Hillary has clinched the Democratic nomination, the many voters who have been inspired by Bernie need to turn their attention and enthusiasm to the next, critical battle—electing Hillary and defeating Donald Trump. And while many will understandably feel disappointed that Bernie is not the Democratic candidate, there’s a strong progressive case for supporting Hillary.

It starts, of course, with the need to trounce Trump. Never before in our history has such a demagogic, unqualified, divisive candidate been this close to leading the most powerful country in the world. Trump has no experience governing, little apparent knowledge of the many complex issues facing the nation, and a temperament wholly unsuited to the office. He has built his candidacy on the politics of division: specifically, in his commitment to build a wall at the US-Mexican border, and more generally, through his denigration of women, Muslims, Latinos, and the disabled. Paul Ryan conceded on Tuesday that Trump’s criticism of the judge hearing the lawsuit against Trump University was “textbook” racism—but Ryan nonetheless continues to endorse him. The prospect of Donald Trump leading this country should be more than enough reason for progressives to back Hillary, and to do so as if the future of the nation depends on it—because it does.

And it’s not just about beating Trump. If progressives come out in force for Hillary, there is a real possibility that Trump will be so decisively rejected that the Republicans could lose their hold on the Senate and even the House of Representatives—outcomes that are essential to making progressive reform possible on a wide range of issues. Trump’s negative coattails could also play out in the states, allowing Democrats to regain control of some state governments. But this will only be possible if progressives strongly back Hillary.

The progressive case for Hillary doesn’t end with opposing Trump. Primary campaigns tend to emphasize the differences between candidates—and there are undeniably differences between Sanders and Clinton. But on virtually all the issues progressives care about most—economic inequality, racial justice, global warming, an economy that works for all, criminal-justice reform, healthcare, and women’s rights—Hillary’s values are largely in keeping with ours. She wants to reduce inequality, overturn Citizens United, end mass incarceration and racial profiling, reform our broken immigration system, advance healthcare for all, address climate change responsibly, and protect women’s right to choose.

On foreign policy, Hillary is undoubtedly more hawkish than Bernie—and while his commitment to civil liberties and privacy is unquestioned, hers is less self-evident. But on most issues we care about, the differences between Bernie and Hillary are more strategic than substantive. Where Bernie demands radical change now, Hillary urges incremental reforms. On healthcare, for example, she fully supports meaningful healthcare for all. But she warns that reopening the healthcare debate by pressing for a single-payer system, as Bernie has urged, is not just unrealistic in today’s political climate, but could jeopardize the gains we made with the Affordable Care Act. Ever since the ACA passed by a single-vote margin, Republicans have been trying to reopen the topic of healthcare so that they can kill it. Stressing the danger in reopening a debate that we barely won in more favorable circumstances, Hillary would instead defend the ACA, while fighting to reduce costs and expand coverage. That’s a less inspiring goal, to be sure—but it’s a more realistic one.

Similar differences can be found across the board. Bernie’s an idealist; Hillary’s a pragmatist. Progressives understandably argue that the second Gilded Age requires radical change, not moderate pragmatism. But when one looks back at the progressive reforms that have succeeded in this country, they have virtually all come about incrementally, not through revolutionary moments.

Take, for example, marriage equality. Activists marvel at how speedily gay-rights activists were able to transform the matter of same-sex marriage from unthinkable to inevitable. It has been described as a revolution in popular attitudes and law. Yet the struggle for marriage equality was in fact a study in patient incrementalism. As I show in my new book, Engines of Liberty, for years gay-rights advocates spent much of their time dissuading gay and lesbian couples from filing federal lawsuits immediately seeking recognition of the right to marry, because they felt that the time was not yet ripe. In the meantime, gay-rights groups embarked on a strategy of gradual reform that lasted decades.

The campaign involved making it safe for gays and lesbians to “come out,” both legally and culturally. It included encouraging news outlets and the entertainment industry to include positive images of gays and lesbians. It featured modest reforms in state family laws, such as allowing gay and lesbian couples to adopt, and limited “domestic partnership” benefits from sympathetic corporations, towns, and states.

Only after they had made sufficient progress on such measures did gay-rights advocates sue for marriage. Even then, they sued only in state courts, and only in the most progressive states. And they restricted their claims to state law, in order to avoid the possibility of Supreme Court review. (The US Supreme Court has final say on federal constitutional claims, but each state’s highest court has the final say on matters of state law.) They started in Vermont, where they won “civil unions.” They then turned to Massachusetts, where, in 2004, they won the first judicial decision anywhere recognizing a right to marry for same-sex couples. They took those arguments next to Connecticut, Iowa, and California, where they won similar victories—and to several state legislatures. Only after they had developed sufficient momentum in the states, and in the court of public opinion, did they bring the issue to the US Supreme Court—where, as the world knows, they won in Obergefell v. Hodges, almost exactly a year ago. In short, this “revolution” began in earnest in the 1990s, and built on advances made by AIDS activists and early gay-liberation advocates that dated back many decades earlier.

Similar stories can be told about women’s suffrage, progressive labor laws, healthcare for the indigent, the dismantling of segregation, and police reform. The struggle for justice is long and slow. It is built on small, pragmatic steps in the right direction. It is easy to be frustrated by this fact, and to be inspired by those who promise radical reform immediately. But that’s not the way we have won most of the advances that progressive support. Hillary understands that. She deserves our support.