WASHINGTON -- Progressive Democrats are growing increasingly concerned that their preferred presidential candidates Elizabeth Warren and Bernie Sanders risk splitting the movement's vote and handing the Democratic nomination to Joe Biden.
The anxieties have led to calls by some for one of the two candidates to drop out before the March 3 "Super Tuesday" contests and endorse the other, in order to coalesce the left behind one standard-bearer. But others reject that approach and say both Sanders and Warren should stay in to amass delegates and join forces at the nominating convention in July.
"A movement can't have two leaders. There needs to be one going into Super Tuesday," said Sean McElwee, a progressive organizer and co-founder of the research firm Data for Progress, who called for a pre-Super Tuesday winnowing to unify behind one candidate.
Larry Cohen, a former union leader who chairs the pro-Sanders group Our Revolution, called that a "terrible strategy." He wants Democrats to nominate Sanders or Warren over a moderate Democrat, but said both should continue to campaign through the primary calendar, rack up delegates, and contest the convention if needed.
The dispute comes as Biden remains the front-runner, in part thanks to strong support from black voters who have picked the nominee in every Democratic primary since 1992. His enduring lead concerns progressives who view 2020 as a rare opportunity to redefine the party in their populist image after decades of nominating centrists such as Barack Obama, John Kerry and both Bill and Hillary Clinton.
Sanders and Warren round out the top three in national polls. Iowa, the first contest, is highly competitive -- a poll released Friday by the Des Moines Register and CNN found Sanders leading the pack with Pete Buttigieg, Warren and Biden closely behind, but a separate survey published Monday by Monmouth showed Biden ahead of his rivals.
And it's not clear Sanders and Warren would team up. A longstanding nonaggression pact between the two appeared to fizzle over the weekend after Politico reported that Sanders volunteers were directed by the campaign to tell voters that Warren's base is limited to upscale and educated people, to which Warren told reporters she's "disappointed to hear that Bernie is sending his volunteers out to trash me." Sanders blamed staff for the move.
Recent polling by Morning Consult found that Warren is the top second-choice preference for Sanders voters nationally, and that Sanders is the top second-choice preference for Warren voters. But the survey showed that Biden would be the second choice for about one-fourth of each candidate's supporters.
Cohen argued that if Sanders and Warren combine for a majority of the pledged delegates they'll have a persuasive argument at the July convention that one of the two movement progressives should be the nominee, even if Biden leads all other rivals in the delegate count.
"I would totally oppose either one dropping out. It'd be a huge mistake," Cohen said. "Their voters do not overlap -- they're not a single circle. There's a huge number of voters who wouldn't even vote for the other. So you need to maximize the elected delegates for the two candidates through June," when the primaries finish.