The night that Bernie Sanders launched his 2020 run for president, I wrote that “the time to make your decision is now . . . You’ve had two years to get ready for this. It’s time to fight.”

When Joe Biden launched his campaign, I wrote that he is

guaranteed to win if the divided opposition can’t unite around another candidate. . . . Every indicator we have says that Joe Biden is the candidate to beat, and every indicator we have points to one candidate as the best chance to beat him. It’s still Bernie.

Since then, I’ve repeatedly argued that socialists should support the socialist, that socialists should not support Elizabeth Warren, and that we should not support the ridiculous truce:

Sanders should try to win as many delegates as possible . . . This means competing with Joe Biden, Pete Buttigieg, and, yes, Elizabeth Warren.

This is not, incidentally, a rare position among Sanders supporters: by January 2019, for example, DSA’s Exploratory Committee for the 2020 Presidential Primary was already arguing that “it is essential that DSA get involved in this campaign as early as possible.” The resolution to back Sanders (and only Sanders) passed in early March by a landslide three-fourths majority. Similarly, about 50 percent of respondents to an informal poll I ran on Twitter recently reported that they had “opposed Warren from the beginning” and exclusively backed Sanders.

Nevertheless, people who support or sympathize with the candidacy of Elizabeth Warren have continued to oppose the effort to rally voters behind Biden’s best and most viable opponent. I’m not interested in relitigating here why I think this has been a mistake. Instead, I just want to lay down a marker.

D.D. Guttenplan:

At some point, we probably will have to choose. The Iowa caucuses in early February should help clarify matters, and the New Hampshire primary the following week is a test of strength both Sanders and Warren need to win.

Hamilton Nolan:

. . . since the important thing is that either Bernie or Warren win, whichever of them is losing by Super Tuesday — March 3, 2020, when a slew of important states hold their primary votes — should drop out and throw their support behind the other.

Julian Brave NoiseCat:

If either fails to make a strong showing in the first three primaries — signaling they have no real chance at the nomination — they should probably drop out and throw their support to the other.

I could go on. Repeatedly, advocates of this “truce” have conceded that the grim realities of delegate math must eventually prevail over indecision and ambivalence. I think it’s clear that these people are not going to end their campaign for Warren just days before the first votes are cast. But here, I want to propose — no, beg for — a compromise:

Please, for the love of God, do the math and end this after Iowa.

As it stands right now, Bernie Sanders is likely to win around 1,250 delegates, and Elizabeth Warren, 463. Even if we imagine some improbable scenario where one gets to claim all of the delegates that the other wins, this only gives us 1,713 delegates between them. That’s nearly 300 short of an outright majority — and it’s even less than Biden’s likely total, 1,750.

Delegate pooling cannot beat Biden. It doesn’t get you a majority, or even a plurality. The only way anyone can beat Biden at this point is if they significantly over-perform expectations, and the obvious way that happens is if they build a head of steam in the early states and then dominate on Super Tuesday. That just can’t happen if Sanders and Warren are splitting delegates in New Hampshire, South Carolina, and Nevada.

Let me be clear: I don’t think that a Warren win would be an acceptable outcome, I don’t think she would collaborate with Sanders to beat Biden, and I absolutely think that Sanders should stay in all the way until the convention regardless of what happens before then.

But if you’re a Warren voter who says that your priority is beating Biden, you need to recognize the importance of building momentum immediately. No kicking the can even further down the road. No appeals to “symbolic” or partial victories. If Warren loses in Iowa, she should end her campaign — and even if she doesn’t, anyone who wants to stop Biden should get behind Bernie Sanders. Or better yet, they should get behind him now.