2024 election updates: Manchin the latest to call on Biden to end reelection bid

"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."

In his first public event since taking questions from reporters in an open presser on Thursday night, President Joe Biden is heading to the Motor City.

Biden will head to Detroit, Michigan, for campaign-related activities on Friday.

After a day of events, Biden will then travel to the Dover, Delaware, airport as he makes his way to his home in Rehoboth Beach.

Former Democratic House Rep. Jane Harman called President Biden's press conference Thursday night a "solid" performance.

"I thought Biden's performance tonight was solid. Yes, there was one gaffe and there was a gaffe earlier today. I don't think it's been a secret for 40 years that he is gaffe prone, so I wouldn't judge him that way. I thought his answers on China and on Ukraine were nuanced and thoughtful and proved what experience he has and what a nuanced mind he has," Harman told ABC News Live Prime anchor Linsey Davis. "Having said that, I'm not going to pretend that the poll numbers are great, and I'm not going to pretend that some of the concerns are invalid, but ... I think we have to be pretty practical here."

Harman then pointed out Biden's desire to stay in the race, his record, which she called "excellent," and the uncertainty of what would happen with the Democrats if he left the race.

"Chaos plays right into Vladimir Putin and Donald Trump's playbooks. And let's not forget, there could be malign influence going on here," she told Davis. "And a lot of the information out there could be domestically driven, or it could be foreign, malign influence."

Regardless, Harman said she thinks Democrats will have a "private conversation soon."

"I'm guessing Nancy Pelosi will be in the room, and she's a highly respected vote counter," Harman continued. "I give her a lot of credit. I served with her for a long time, and we're still in active touch. And we'll see; I mean, he said if he can't win, he will leave the race. If he can't win, he has to be persuaded of that. But if he can't win, who can win? This is not a conversation about Biden leaving. It's a conversation about the Democratic ticket winning."

Rep. Lloyd Doggett of Texas, the first sitting House member to call for President Biden to step aside, told ABC News Live Prime anchor Linsey Davis that following Thursday's press conference, his opinion hasn't changed.

"I thought the president did a good job. I think he clearly is the most qualified person to handle our international relations. But the question before us -- is he the most qualified person to turn around the undecided and the independents who have refused to join him over the past year and now complicated by the setback when we needed a surge that he had during the debate," Doggett said. "Every time there's a slip, a Vice President Trump instead of Harris, a Putin instead of Zelensky, people will focus on something that might not have even been noticed at past times. And to the extent over the coming months that all the attention is on whether he is fit and able to do this job instead of on Trump's lies, we will be set back."

Doggett, directing his comments to Biden, said the polls don't support a top-of-the-ticket win.

"And, Mr. President, just as you deal with the reality of conflict around the world, deal with the reality of the numbers here. And when you look at those numbers, we don't see a path forward for a Democratic Congress and a White House that is occupied by someone of President Biden's skill, but is instead occupied by a criminal and his gang."