Bernie Sanders spoke to the media Wednesday after Joe Biden took the lion’s share of delegates in Tuesday’s primaries, and the Vermont senator all but acknowledged that he won’t be the Democratic presidential nominee. After talking about the electorate’s support for the issues that have driven his campaign and the importance of appealing to young voters, he said this:

While our campaign has won the ideological debate, we are losing the debate over electability. I cannot tell you how many people our campaign has spoken to who have said, and I quote, “I like what your campaign stands for. I agree with what your campaign stands for. But I’m gonna vote for Joe Biden because I think Joe is the best candidate to defeat Donald Trump,” end of quote.
We have heard that statement all over this country. Needless to say, I strongly disagree with that assertion, but that is what millions of Democrats and independents today believe.

The reaction in some quarters to Biden’s string of victories has been to urge Sanders to get out of the race. While they were still counting votes on Tuesday, House Majority Whip James E. Clyburn (D-S.C.) even said that “if the night ends the way it has begun, I think it is time for us to shut this primary down, it is time for us to cancel the rest of these debates.”

Sanders shouldn’t listen to that. It’s true that it will be all but impossible for him to become the nominee unless Biden suffers a health emergency or something else cataclysmic happens. But staying in the race — so long as he does it in the right way — will be good for him, good for the causes he believes in, and good for Democrats.

To begin with, candidates should stay in the race as long as they want to. If Sanders has the funds to pay his staff and he wants to continue to use the megaphone he has to advocate what he cares about, he has every right to do that.

At this point, staying in the race serves an ideological purpose: keeping Biden honest.

Over the course of this campaign, Biden has taken plenty of positions that are farther to the left than he had earlier in his career; health care is just one example. The former vice president did it because it’s what politicians do: He moved toward the center of gravity in his party, which is in a different place today than it was 20 or 10 or even five years ago, even if that center of gravity is still to the right of Bernie Sanders.

But it’s legitimate to doubt Biden’s commitment to the policies laid out in the “Joe’s Vision” section of his website, because he’s relatively new to some of them and he doesn’t spend all that much time talking about them on the stump.

So the more Biden has to talk about policy and advocate the positions he has taken, the more he will feel that he has made commitments on which he can’t backtrack. You may already be aware that presidents keep most of the promises they make on the campaign trail, and the more loudly they make those promises, the more difficult they are to break.

But it’s not just about the details. When Sanders debates Biden on Sunday — and when he campaigns on the stump — he should put the focus on first principles. Instead of bickering about how to pay for this or that health-care plan, talk about the moral urgency of our health-care crisis, about why gross inequality is not inevitable, about how important it is that we address climate change.

The good news is that Sanders is really good at that. He already does it. His rhetoric always begins with questions of morals and a vision of how our society could be better.

And he can do it in a way that doesn’t hurt Biden’s chances in the general election. It’s the difference between, “Joe, you need to go farther to fight inequality, which is why my proposal is better” and “Joe, you’re a corporate sellout and nobody should vote for you.”

Sanders may not get Biden to come over to single-payer health care, but he can get him to commit to making sure that no one goes without health coverage one way or another. There are a host of issues on which Sanders could challenge Biden to commit to serving progressive ideals — and if it’s just the two of them on a stage, it’ll be more difficult for Biden to say no.

And this is important for Sanders: He can use this time to model for his own supporters how to exercise influence, not by angrily declaring that if your candidate didn’t win then it’s all a disaster and we might as well have Trump for four more years, but by staying engaged.

We’re reaching the point where a vote for Sanders is more expressive than instrumental — and that’s fine. If Biden is going to be the nominee and your state hasn’t voted yet, there’s no reason for you not to cast your vote for Sanders if he’s your favored candidate. Every additional vote he gets is a message to the party about the desire to take action on the issues he has campaigned on.

Use the Post Opinions Simulator to pick a state and see what might happen in upcoming primaries and caucuses.

After all, if Biden becomes president, a good deal of the next four or eight years will be about a struggle over how far to go on key issues. If you’re a Sanders supporter, you should want to participate in that struggle.

Don’t just resign yourself to Biden appointing some guy from Goldman Sachs to be treasury secretary, convince him that his party won’t stand for it. Don’t just wait to be angry at Biden for compromising on climate action, let him know what the political cost will be. Don’t just assume he’ll be terrible and look forward to saying “I told you so,” pull the Democratic Party in your direction even if it requires more work and organizing.

If your reaction is that none of it will matter without Sanders, then you weren’t part of a political cause, you were part of a cult of personality.

Let’s hope Sanders himself doesn’t see it that way, and chooses to go out in a way that doesn’t tear Biden down, but instead pushes him to be better.

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