“I understand that people have favorites,” Jayapal, who has not yet endorsed in the race, told POLITICO after the meeting, which included representatives from top congressional allies of Warren and Sanders along with longtime advocates on the issue like National Nurses United. “We are better off having two strong presidential candidates endorsing Medicare for All than having one.”

Warren has done a delicate dance on the issue over the past month, releasing a detailed financing plan that she said would avoid middle-class tax hikes, then following up with a two-stage transition plan in a nod to those concerned about upheaval in the health care system. Though some established Democratic strategists said Warren's plans could give her more flexibility in a general election — by initially passing a robust public option and then trying to pass a full single payer bill later in her term — some progressives saw the maneuvering as too clever by half.

But Jayapal and other people at the meeting said sniping at Warren will only hurt the cause.

“I think everyone left [the meeting] knowing the overall objective is the same and Warren is as committed as she’s ever been to achieving Medicare for All,” said Wendell Potter, president of the group Business for Medicare for All, who attended the gathering.

Ady Barkan, one of the country's most prominent Medicare for All advocates who is dying of terminal ALS, made a similar plea as he endorsed Warren on Wednesday. "We should keep perspective," he wrote to fellow progressives, after laying out his reasons for preferring Warren's health care strategy. "We are, ultimately, on the same side. When the dust settles, Warren will enthusiastically endorse Sanders, or vice versa, and then we will need to all struggle together, as one progressive movement."

"We are better off having two strong presidential candidates endorsing Medicare for All than having one," Rep. Pramila Jayapal said. | Andrew Harnik, file/AP Photo

In the Capitol Hill meeting, Jayapal also expressed dismay at the online backlash Barkan received from some on the left for his previous positive assessments of Warren's health plans, and urged unity going forward. Jayapal and about 20 members of the Congressional Progressive Caucus also attended a separate Medicare for All closed-door briefing Tuesday. Informed by new polling paid for by the Progressive Change Institute in partnership with Public Citizen and Business for Medicare for All, the session offered strategies to respond to the most common attacks on Medicare for All, particularly that it will result in massive tax hikes and eliminate private insurance.

“This polling is really helpful because now we know that we can proceed with confidence,” said Adam Green, a Warren supporter and co-founder of the Progressive Change Campaign Committee who helped present the polling results to the members of Congress.

The polling session and Jayapal’s meeting Tuesday were two of several moves by the left in recent weeks to try to regain the offensive in the battle over Medicare for All. Some progressives have also felt that they need to challenge the alternative offered by moderates — a public-option plan dubbed ”Medicare for All who want it” by Mayor Pete Buttigieg — more aggressively. They argue the plan, which polls as more popular than Medicare for All, would continue to leave millions uninsured and still charge many people premiums and deductibles. Warren and Rep. Alexandria Ocasio-Cortez have dismissed the idea as “Medicare for All who can afford it” and “Medicare for Some,” respectively.

Conducted by Democratic pollster Margie Omero, the survey presented Tuesday found that the three strongest arguments for single-payer are that people would no longer die because they couldn’t afford medicine or care; that the U.S. would no longer be the only developed country without a universal health system; and that families would no longer struggle to provide long-term care for seniors and people with disabilities. The poll also found that most of the rebuttals to attacks about tax hikes or eliminating private insurance survey are about equally effective, so progressives urged members to confidently use the arguments they are naturally drawn to in order to regain control of the narrative.

“The most important thing is to make the case,” Green said.

Single-payer advocates also stressed that supporters need to end the friendly fire between Warren and Sanders supporters and redirect it toward the Democratic candidates who oppose the idea. “The enemy here is not one or the other of them,” Jayapal said of Sanders and Warren. “It is the entrenched interests, and the groups that are rallying around them, including some of our Democratic presidential candidates who are really doing a disservice to the American people.”

Several progressive members of Congress seemed to take the message to heart. “I think it's excellent,” Rep. Ilhan Omar (D-Minn.) said of Warren’s plan, despite having endorsed Sanders in the race. “There are many approaches to how we transition into this.”

“Obviously, I think it should be done in one bill, but when you look at the plans they have the same blueprint,” added Rep. Ro Khanna (D-Calif.), who is also a co-chair on Sanders’ campaign.

The Medicare for All movement has gained tremendous ground since Sanders ran on the plan in 2016, with more congressional co-sponsors than ever and Barack Obama dubbing it a “good, new idea” for Democrats last fall. But the 2020 presidential primary’s intense focus on the issue has put single-payer backers on their heels. Several of the candidates or former candidates who originally embraced the plan, including Sens. Kamala Harris and Kirsten Gillibrand, have backed away from it. And Warren has been consumed by the issue for weeks.

Now, Democratic and outside groups are hoping to go to the grassroots to take back control of the narrative. The 150,000-plus member nurses union, which endorsed Sanders in the 2020 primary and backed him in 2016, has mounted a 50-state organizing campaign to try to redirect the conversation away from Medicare for All’s cost and impact on private insurance and towards its benefits. They say they’ve knocked on 20,000 doors so far this year, and are in the midst of training thousands of volunteers.

“We’re seeing the presidential debates really muddying the waters on Medicare for All,” said Jasmine Ruddy, the lead Medicare for All organizer for the nurses union. “But that’s not what we’re seeing in our work out in the community, when we’re canvassing,” she added optimistically. “These conversations cut through the misinformation.”