While President Joe Biden has yet to directly address the growing disquiet in the Democratic Party about his viability as the party's candidate following a universally criticized debate performance last week, the calls from current and former lawmakers, as well as key party players, are getting louder.
Many prominent Democrats have said they stand by the president and only one member of Congress has called for him to withdraw. Still, in TV appearances, public statements and interviews with ABC News, key party players have increasingly expressed serious concerns about Biden's mental acuity and pressed for reassurance.
Some of the clearest calls for Biden to step aside have come from his prior Democratic primary challengers. Former Ohio congressman and 2020 Democratic presidential candidate Tim Ryan wrote in an opinion piece published Monday night in Newsweek that Biden should step aside and that Vice President Kamala Harris should become the Democratic nominee.
MORE: 5 takeaways from striking Biden-Trump presidential debate"He also promised to be a bridge President to the next generation … Regrettably, that bridge collapsed last week," Ryan wrote of Biden's debate performance. "Witnessing Joe Biden struggle was heartbreaking. And we must forge a new path forward."
Former Obama administration Secretary of Housing and Urban Development Julian Castro, who served in the Obama administration and also ran against Biden in 2020, said on MSNBC on Tuesday that Democrats should find a "stronger" nominee than Biden.
"I think the Democrats would do well to find a different candidate," Castro said.
And Independent Sen. Joe Manchin, the once high-profile moderate Democrat from West Virginia, had to be talked out of going as far as Ryan and Castro, sources told ABC News.
Manchin told a handful of allies that, after Biden's debate disaster, he was ready to go on a Sunday news show and call on him to step aside. But when word got out, senior Democrats talked him out of it, two people familiar with the private discussions told ABC News.
This revelation was first reported by The Washington Post.
The White House said Tuesday it wants to "turn the page" on Biden's debate performance.
"First of all, I want to say we understand the concerns," White House press secretary Karine Jean-Pierre said during Tuesday's press briefing. "We get it. The president did not have a great night, as you all know."
"But I will say this, and the president said this over the past couple of days, certainly right after the debate: He knows how to do the job," Jean-Pierre said, "and he knows how to do the job not because he says it, because his record proves it."
MORE: White House seeks to 'turn the page' after Biden's debate performance with events, interviewJean-Pierre told reporters on Tuesday that Biden will speak with Democratic lawmakers and governors on Wednesday to address their concerns before he travels to battleground states Wisconsin and Pennsylvania this weekend.
A group of Democratic governors led by Minnesota Gov. Tim Walz huddled on Monday on a call to touch base post-debate, per several sources familiar with the matter.
According to two people briefed on the call and one governor who attended the meeting, some governors did express frustration over the president's debate performance -- as well as the lack of outreach from the president directly to some of the governors on the call. However, one source familiar told ABC News that the Biden White House is in "constant touch" with governors and their teams.
Some Democrats have called on Biden to abandon teleprompter appearances and answer questions at a news conference or in a sit-down interview.
Biden is likely to address these concerns and more in his first TV interview since the debate with ABC News' "Good Morning America" co-anchor and "This Week" anchor George Stephanopoulos. A first look of the interview will air Friday, July 5, on "World News Tonight with David Muir," with portions airing on "Good Morning America" Saturday and Sunday as well.
The party panic began immediately after the debate, as Democrats expressed alarm about the president's performance -- most requesting to speak anonymously. Some prominent party leaders, including former Presidents Barack Obama and Bill Clinton and House Speaker Hakeem Jeffries, issued brief statements in Biden's support.
By the weekend, though, other prominent figures in the party began to break their silence, some openly raising doubts.
"There are very honest and serious and rigorous conversations taking place at every level of our party," Democratic Rep. Jamie Raskin said on MSNBC Sunday, "because it is a political party, and we have differences in point of view."
MORE: Rep. Jamie Raskin: Democrats having 'a serious conversation' following Biden's debate performanceOthers defended Biden with the talking point that he simply had a "bad night."
"I think it was a weak debate performance by President Biden," Democratic Sen. Chris Coons, a co-chair of the president's reelection campaign, said on ABC News' "This Week."
"He had a scratchy, rough voice. He answered a few questions in ways that were not the most forceful, but I think side-by-side, Donald Trump had a horrifying debate performance. I do think it's for Joe Biden to make any decision about his campaign, his debate prep, his path forward."
MORE: Coons: Biden is 'the only Democrat who can beat Donald Trump'In separate weekend appearances, former Speaker Nancy Pelosi and House Majority Leader Hakeem Jeffries expressed support for the president, playing down the significance of Biden's debate-night flub. Several of the talented, young Democratic governors touted as possible replacements for the president -- including Michigan's Gretchen Whitmer, California's Gavin Newsom and Pennsylvania's Josh Shapiro -- also publicly backed Biden.
But this week, other Democrats weighed in with questions about the president's fitness.
Longtime Democratic Sen. Sheldon Whitehouse told WPRI, a Rhode Island CBS station, on Monday that he was "pretty horrified" by the debate. He said that people need to be assured "that the president and his team are being candid with us about his condition, that this was a real anomaly and not just the way he is these days."
"I think people want to make sure that this is a campaign that is ready to go and win," Whitehouse added.
And Texas Democratic Rep. Lloyd Doggett called on the president to withdraw from the race on Tuesday, saying "President Biden has continued to run substantially behind Democratic senators in key states and in most polls has trailed Donald Trump. I had hoped that the debate would provide some momentum to change that. It did not."
Doggett is the first Democrat in Congress to say Biden should step aside.
As pressure has built, even Biden's staunchest allies have acknowledged the legitimacy of concerns about his acuity -- and called on the president to agree to tough interviews with the press to assuage them.
In a Tuesday interview with MSNBC's Andrea Mitchell, Pelosi acknowledged "I think it's a legitimate question to say: Is this an episode or is this a condition?"
"My recommendation is for him to have some interviews with serious journalists," Pelosi said. "No-holds-barred, any question's fair, and just sit there and be Joe. Show your values, show your knowledge, show your judgment, show your empathy for the American people."
Pressed by CNN's Jake Tapper -- one of the hosts of the first debate -- in a Monday night interview, Coons said Biden "needs to reassure folks with repeat performances in public that he is up to this task."
"I have not seen evidence that our president is not up to the task of running for and continuing to serve as president, so that's something that is up to our president to prove in the coming weeks," Coons said. "But I do think he has the strongest record in his first three years that any of us could imagine."
Democratic National Committee members told ABC News that the party needs to stop the hand-wringing.
"Let's get to work and stop whining," said Rules and Bylaws Committee member Maria Cardona.
MORE: Donald Trump is having a very good few days. Republicans are giddy.Michael LaRosa, former press secretary to first lady Jill Biden and a special assistant to the president until mid-2022, said he believes that only Biden's tight inner circle, compromised mostly of his family, were the only ones who could hold sway over his political future.
"It's going to be up to Biden, to the Biden family and the Biden orbit. Whether they care more about Joe Biden, or more about the Democratic Party, and if they can, if the Democratic Party can win with Joe Biden, they need to make that assessment," he said.
And he echoed the call from many other Democrats that if Biden wants to press on, he needs to get in front of voters, off-script.
"You don't get a second shot at your first debate," he went on. "And you can't get away with pool reports and teleprompters for the next four months."
ABC News' Rachel Scott, MaryAlice Parks, John Parkinson, Oren Oppenheim, Isabella Murray, Selina Wang and Luke Barr contributed to this report.