Well, we’ll always have Michigan….

A week after Bernie Sanders stunned pollsters with a victory that nobody predicted, lifting his campaign—and his supporters’ expectations—those hopes came crashing down to earth yesterday with defeats in Florida, Ohio, Illinois, and North Carolina. Hillary Clinton’s late-breaking win in Missouri gives her a clean sweep on a night that was meant to mark the turn in the tide for Sanders, who poured time and money into Ohio, where Clinton took every big city on her way to a convincing 14-point victory, and Illinois, where Sanders hoped to profit from dissatisfaction with Chicago Mayor Rahm Emanuel, a longtime Clinton ally. Though voters did punish Cook County prosecutor Anita Alvarez for her handling of the police shooting of Laquan McDonald, favoring challenger Kim Foxx by a margin of 2 to 1, Clinton carried Cook County by a comfortable 8 points.

Yes, it’s true that the rest of the primary calendar is more favorable to Sanders—who has won more states, garnered many more votes, and has a larger share of the delegates than any of the Republicans challenging Donald Trump. Whose presumptive grasp on his party’s nomination is denied almost daily by the same media who have been burying Sanders—when they could be bothered to write about him—from Iowa onward. We never said this was going to be easy—or a fair fight.

Hillary Clinton has always been the favored candidate of the party establishment. And unlike 2008, when the powerful Cook County portion of that establishment broke for Obama, a favorite son, this time the establishment remains unified in the face of the Sanders insurgency. Which would be reason enough for Sanders to carry on his fight all the way to Philadelphia, even if it really were mathematically impossible for him to win the nomination—a point we are still unlikely to reach before California votes on June 7. The strength of Sanders’s challenge, and the enthusiasm of his supporters, have already pulled Hillary Clinton off dead center on police violence, trade policy, access to education, and making the wealthy pay their share of taxes. 

As long as he stays in the race, and stays true to his beliefs, Sanders will keep winning those arguments, even if Clinton’s willingness to steal her opponent’s best ideas—and even some of his best lines—help her to win voters who will be crucial in defeating Trump in November. Turnout remains the Democrats’ Achilles’ heel: In Ohio, where Trump came second, he still got more votes than either Democrat. Clinton herself seems to get this, and yesterday declined to endorse calls for Sanders to drop out. Any other course would leave Trump in sole possession of the media for the next four months.

Speaking of the Donald, it also seems odd that while his impact on the Republican party is endlessly analyzed, almost nothing has been said about the way Trump’s likely nomination has influenced Democratic primary voters. My own guess is that fear of Trump probably carried Clinton over the line in Illinois and Missouri.

Keeping Clinton from reverting to a neoliberal default isn’t the only reason for Sanders to stay in the race—or the most important. As Sanders has always said, his aim is “a political revolution.” Winning the nomination would be nice, but is neither necessary nor sufficient to bring that about. Building a nationwide, durable network of mobilized, active supporters prepared to keep working for universal healthcare, a living wage, ending Wall Street welfare and America’s endless wars—including the drug wars—in numbers great enough to Occupy the Democratic Party and take it back from its corporate funders is absolutely crucial. So, too, is the difficult work of stitching together movements like #BlackLivesMatter, Fight for 15, immigrant rights, climate justice, and voting rights into a coalition prepared to march together, vote together, and transform our politics—and our country. Yet that is the task we face.

Are the odds against us? Of course. That’s what it means to live inside a rigged system. But remember where we were only a few months ago. With each primary victory—and each close call—Sanders shows us our own strength. With each packed rally we see the claim that socialism is un-American exposed as a lie, that a world where no one starves, healthcare is not rationed by wealth, and energy companies aren’t allowed to rape the earth for profit and leave the rest of us to take the consequences is not only possible but popular. 

Why cut off that momentum? Especially when, as Daniel Cantor of the Working Families Party points out, Sanders actually keeps getting stronger: “Bernie’s North Carolina performance was 15 points better than his South Carolina performance last month, and 5 points better than his Virginia performance two weeks ago. Meanwhile, the margin in Cook County, Illinois, is half of that in Wayne County, Michigan.”

So we fight on—to July, November, and beyond. For the nomination, so long as that remains a possibility. For our country—which may in November face as stark a choice as any in our lifetimes. And for our future, which is far too precious a prize to abandon for the sake of a few thousand votes.