WASHINGTON — As top Democrats offered a public show of support for President Joe Biden throughout the weekend, his advisers worked privately Sunday to push back against suggestions that he step aside, with his campaign manager describing the mechanics of replacing him on the ticket as messy and impractical. 

During a tense call with a group of about 40 of Biden’s top financial backers, campaign manager Julie Chavez Rodriguez laid out what could and could not be done with the campaign’s infrastructure if Biden were to step aside while emphasizing throughout the call that he had no intention of doing so.

Most of the campaign’s significant war chest would fall to Vice President Kamala Harris, Chavez Rodriguez said, according to two people familiar with the discussion. Only a smaller pool of money would be kept by the Democratic National Committee.

As several donors posited what a participant derisively referred to as fanciful “West Wing”-type scenarios for replacing Biden, Sen. Chris Coons, D-Del., who joined for part of the call, emphasized that the process would be “messy” and predicted that Harris would ultimately end up as the nominee.

Sunday’s call was just one of a series of similar conversations top Biden advisers and campaign leaders have been holding with Democratic officials and donors after Biden’s halting debate performance rattled the party elite.

The conversation was among the more candid the campaign has held with a larger group in recent days, wading into the delicate question of exactly who might succeed Biden if he were to step aside.

Jen O’Malley Dillon, the chair of the Biden campaign, is also set to hold a call with a larger group of donors Monday night, according to two sources familiar with the plans.

Meanwhile, Biden’s family — the people who have most influence on him — met and discussed the future of his campaign during a long-planned gathering at Camp David, Maryland, NBC News first reported.  

The message from Biden’s children and grandchildren, together for a photo shoot Sunday with famed photographer Annie Leibovitz, was to “keep fighting,” said two sources familiar with the discussions. 

In recent days, some of Biden’s family members have expressed deep frustration with the aides and advisers responsible for preparing him for the debate, which carried over into conversations over the weekend, multiple sources said. A senior Biden adviser called such suggestions false, while a campaign spokesperson said Biden still has confidence in his most senior staffers. 

“The aides who prepped the President have been with him for years, often decades, seeing him through victories and challenges. He maintains strong confidence in them,” Biden campaign spokesman Kevin Munoz said in a statement.  

The campaign’s public posture Sunday was to draw attention to the positive, or at least neutral, response that voters and grassroots supporters have had to Biden’s first debate against former President Donald Trump.

“Every time Donald Trump opened his mouth, those dials dropped. They just absolutely plummeted,” Biden campaign pollster Molly Murphy said on MSNBC, referring to live panels the campaign conducted Thursday. “[Voters] felt like the president came across as someone who cares about middle- and working-class Americans, and when compared to Trump he came across as more presidential, more likable, more truthful.” 

House Minority Leader Hakeem Jeffries, D-N.Y., said in another MSNBC interview: “It certainly was a setback. But of course I believe a setback is nothing more than a setup for a comeback.”

During the call with donors, Chavez Rodriguez noted that the campaign has raised $33 million since the debate and even received hundreds of new applications from people wanting to join the campaign.  

Coons also made a “fiery” case for Biden, pointing to his performance during recent international gatherings and his campaign rally in North Carolina on Friday to say there’s no evidence that Thursday’s debate was anything other than a bad night. 

One participant said that many on the call were still firmly behind Biden but that “a lot of the participants are frightened.” 

“There were some tough comments from those on the call. Some were upset that they are just hearing campaign talking points,” the participant said, adding that some donors even asked about having their contributions refunded.

Another senior Democratic official who has spoken directly with Biden and members of his campaign team said he has been reassured about Biden’s staying in the race and characterized his team’s posture as “powering through.”

But he also said he has had a lot of “one-off texts and conversations” with his peers and predicted the next two weeks would be critical.

“We’ll have polls and we’ll have a money count. If they’re good, it leans that he [remains in the race]. And if it’s not, all bets are off,” the official said. It will be “decided on data more than emotion. It’s too early to make the call.”