According to a senior Democratic source, at the Biden campaign briefing on Thursday with Democratic senators, only three senators spoke up to say Biden should stay in the race. The senators also asked for Anita Dunn (a senior adviser to Biden) to be at the briefing and she did not come.

House Democratic Leader Hakeem Jeffries and Senate Majority Leader Chuck Schumer are both sympathetic to the view Biden is on a path to lose to Trump and it would be best if he moved on, the source said. But, the source said, "This is a private play, not a public one."

Former House Speaker Nancy Pelosi has also spoken to Barack Obama about this -- although it is important to say, they talk regularly.

-ABC News' Jonathan Karl

"Joe Biden saved our country once, and I'm joining the growing number of people in my district and across the country to ask him to do it again," Colorado Rep. Brittany Pettersen said in a statement.

The congresswoman urged Biden to "pass the torch" to "one of our many capable Democratic leaders so we have the best chance to defeat Donald Trump."

There are now 18 congressional Democrats calling on Biden to step aside as the party's candidate.

The House Democratic leader, in a letter to colleagues on Friday, said he met with President Biden privately on Thursday evening.

"Over the past several days, House Democrats have engaged in a thoughtful and extensive discussion about the future of our country, during a time when freedom, democracy and the economic well-being of everyday Americans are on the line," Jeffries wrote. "Our discourse has been candid, clear-eyed and comprehensive."

"In my conversation with President Biden, I directly expressed the full breadth of insight, heartfelt perspectives and conclusions about the path forward that the Caucus has shared in our recent time together," Jeffries added.

-ABC News' Lauren Peller

"I am all in. I'm ridin' with Biden no which direction he goes, no matter what method he takes. I'm with Joe Biden," Rep. Jim Clyburn said on NBC News in his first post-press conference interview.

"And if he were to change his mind ... I would be all in for the vice president," Clyburn said.

The congressman, whose endorsement was key to saving Biden's primary campaign in 2020, said Biden has "earned" the right to make his own determination on his political future.

"I am going to give him that much respect," Clyburn said. "If he decides to change his mind later on, then we would respond to that. We have until the 19th of August to open our convention and so I would hope we spend our time now focusing on the record that we would lay out for the American people, remind the American people what is in store if Project 2025 were to become the law in any form. That is where our focus ought to be."