When Senator Elizabeth Warren walked up to Senator Bernie Sanders after Tuesday night’s Democratic debate, refused to shake his hand and exchanged only a few words with her rival 2020 presidential candidate, it seemed like the progressive wing of the Democratic party would sink into more infighting.

But a day later, supporters of both candidates and neutral liberal figures were keen to find some kind of off-ramp.

The fear is that the longer the row goes between the two candidates, the higher the chances that neither of them will benefit and instead a larger pathway to the party’s nomination for the White House will open up for a more centrist candidate like the former vice-president Joe Biden or the former South Bend mayor Pete Buttigieg.

“I think that what is most constructive is that progressives across this country unite in fighting against the corporate wing rather than fighting against each other,” said Charles Chamberlain, the executive director of the liberal political action committee Democracy for America.

“There is way more that unites these candidates than divides them. Only Elizabeth Warren and Bernie Sanders are talking about Medicare for All, a Green New Deal. They’re the ones that are talking about closing the gap between the working class and the millionaire class. These are the only two candidates that are entirely funded by small-dollar contributions instead of big money and private one-on-one fundraisers,” he added.

The feud happened quickly. Last week Warren and Sanders were still acting on a sort of civil detente the two had followed for most of the cycle, refraining from attacking each other. But over the weekend Politico reported on a set of talking points the Sanders campaign had been circulating to organizers urging them to say that Warren’s supporters were really only wealthy Democrats and she would not bring in new voters.

Then another report, from CNN, came out saying that during the 2018 meeting in which Sanders and Warren discussed their interest in running for president in 2020, Sanders said that a woman couldn’t win.

Sanders has repeatedly denied saying that, including when asked about it during the debate. Warren, also during the debate, maintained Sanders did say it. Then, at the end of the debate, Warren approached Sanders and as he outstretched his hand, she didn’t shake it; she started talking and Sanders shook his head. After a few more words, the two walked away from each other.

Neither campaign has offered more information on what was said. Immediately after the debate, Sanders’ senior adviser Jeff Weaver told reporters that he did not know more about what was said but that the two senators remained friends. The exchange did not look friendly, though.

On Wednesday, two hashtags were trending on Twitter: #neverwarren and #warrenisasnake.

Anyone using #NeverWarren is clearly overcome with white privilege and is not and has not been effected by this monstrous administration. We shouldn't be saying "NEVER" about anyone EXCEPT #Trump. Get your 'ish together. #WokeAF — DanielleMoodie-Mills (@DeeTwoCents) January 15, 2020

Yep, let's be clear: if you're tweeting in support of this ludicrous #NeverWarren hashtag, you're not only dumb but you're also telling the world that you're ok with kids in cages and bans on Muslims. https://t.co/VZgA01hzIp — Mehdi Hasan (@mehdirhasan) January 15, 2020

If you wanna sell Bernie, sell his virtues and well. But this thread begins on a morning when #NeverWarren is trending and I’d say the exact same thing if #NeveBernie was trending. Fuck that rank stupidity. And fuck you for deflecting straight-up criticism of that stupidity. https://t.co/1B2396yzHy — David Simon (@AoDespair) January 15, 2020

I'll say it again.

I'll vote for whoever the Dem nominee is.

I think most progressives/liberals feel that way—with the exception of one candidates' base.

That's a problem.

People tweeting #Never Warren are in a cult too, just with a different messiah.https://t.co/ZzMIpmT5GV — John Pavlovitz (@johnpavlovitz) January 15, 2020

The Nebraska Democratic party chairwoman, Jane Kleeb, said fighting between Warren supporters and Sanders supporters was unhelpful.

“We need them – the moderate and conservative wing – represented as well. We often say we need both wings to fly, especially going against Trump. So I think all of the hate that I’m seeing on both sides, both Warren and Bernie supporters attacking each other, is some of the most ridiculous things that I’ve seen this election cycle. None of us were in the room,” she said.

Kleeb added: “I’m sure it was a contentious meeting. But for us to throw stones at each other now weeks before the Iowa caucus is the stupidest move progressives can have because we are strong right now in number.”

Chamberlain recalled that in 2004, just before the Iowa Democratic caucuses, the then Vermont governor, Howard Dean, and then House Democratic leader, Dick Gephardt, were in a heated feud. That paved a way for the then senator John Kerry to win the caucuses and eventually become the Democratic nominee. Kerry went on to lose the election to George W Bush, decisively.

“That’s the risk, that’s what’s at stake here,” Chamberlain said. “So it’s absolutely critically important that at the end of the day progressives need to be united in supporting the progressive candidate against the corporate wing. Because that’s what it’s going to take to defeat Donald Trump in November.”