Lucas Jackson / Reuters

Bernie Sanders’s signature issue is Medicare for All: a vision of state-financed health care for every American. But Sanders’s defeat could drag his issue down with him, instead of it lofting him into the presidency.

Yet he has an opportunity before him at least to advance his idea. The spread of the coronavirus is raising demand for a more socialized approach to health care: free vaccinations, stricter control of insurance companies, paid sick leave, income support for laid-off workers. By ominous coincidence, the number of known COVID-19 cases in the United States passed 1,000 on the same day that Sanders lost primaries in Idaho, Michigan, Mississippi, and Missouri. That sequence of defeats extinguishes any last hope that Sanders could win the Democratic nomination in 2020.

Sanders now faces a crucial choice. He could respond creatively to the political and medical news. He could return to the Senate, and there use his high profile and his massive mailing list to lead the fight for a generous response to the epidemic—achieving, at last, the big legislative legacy that has until now eluded him.

Or he could do as President Donald Trump is urging him to do, not to mention Jill Stein and thousands of bots on Twitter: Continue his doomed campaign for the nomination, not with a view to winning, but with a view to inflicting as much damage as possible on Joe Biden. In 2016, Sanders played an important role in legitimating Trumpist attacks on Hillary Clinton: She was bought and paid for by Goldman Sachs; she’d plunge us into World War III over Syria. In the end, a large group of Sanders voters—perhaps as many as 12 percent—crossed lines to vote for Trump. Unknown numbers of others dropped out of the political process altogether. Trump slavers for a repeat of that performance in 2020.

Amid the accelerating economic decline—and after the Trump administration’s catastrophic mishandling of the outbreak’s initial stages—Sanders may be the only person who can save the presidency for Trump. The question for Sanders now is this: Will he cooperate with Trump?

Every decision can be rationalized. Sanders and his inner circle can surely devise many justifications for extending their fight to help Trump.

But the justifications will be excuses. Everything they say they want to do for their principles and their movement can be better done by building health-care coalitions in the U.S. Senate. The only thing they can actually do by prolonging Sanders’s campaign is sustain Trump in his work of defamation against Biden.

Some Sanders employees may relish that. There has always been a fringe of the Sanders movement that quietly—or not so quietly—prefers Trump to a conventional Democrat. If you fantasize about toppling the American system in a spasm of revolution, or if you regard the U.S. as an evil empire that must be weakened from within before it can be overthrown, then of course you’ll prefer the destructive Trump to a moderate reformer who might improve the system you detest.

But that fringe is a fringe. Most Sanders voters just want a better deal. And in 2020, much more than 2016, Sanders himself has voiced from the start a clear commitment to beating Trump at all costs. The time has come for him to do what he promised—and to turn his back on those supporters who chose Sanders less because they liked him than because they hated the party Sanders sought to lead.

Even as he nears 80, Sanders still has a future. In the next three days, he will decide how that future will be written: whether as the health-care champion he has long wished to be, or as Trump’s deluded tool.

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