In the last week,  progressive group Roots Action quietly began circulating a letter to other left-wing organizations, urging Joe Biden to nominate Elizabeth Warren as his vice presidential pick.

But not everyone is on the same page as the conflict between Warren and Bernie Sanders’ camps continues to roil a progressive left.

“There’s a lot of groups that don’t want to get into that,” Jeff Cohen, a co-founder of Roots Action, said of the reaction to the Warren-for-VP petition. “They’re working on other issues.” He plans to release the petition in a few weeks.

Sanders wasn’t actively pushing Biden to pick a particular person for his No. 2, according to an aide to the senator. On Friday, when asked how his supporters would feel if Biden picked Warren, Sanders did not explicitly advocate for her.

“All I can say is that I think the more progressive the vice presidential candidate that he nominated, the better it would be in terms of the kind of response that our supporters would provide him,” Sanders said.

Warren herself confirmed she’s interested in the job. “Yes,” she said flatly when asked on Wednesday night if she’d accept if Biden asked her.

Cohen said he sees Warren as “the strongest unity candidate” and moderate Senator Amy Klobuchar as “the most divisive choice” for Biden’s running mate. And Sara Nelson, president of the Association of Flight Attendants, has also been singing Warren’s praises in talks with the Biden campaign.

She “would be a wonderful choice,” Nelson said. “We’re watching her leadership play out in real-time during this coronavirus crisis, and she would unite the party.”

Some Sanders campaign officials, even after the contentious primary said Warren is the most viable progressive in contention for Biden’s vice presidential selection.

“I think one of the things we should do as a progressive movement is, given that he can’t pick Bernie — he said he’s going to pick a woman — we should push for the most progressive woman,” Khanna said. “And in my view, that’s Elizabeth Warren.”