Biden's interview fails to quell Democrats' concerns about his fitness

President Joe Biden's Friday night TV interview does not seem to have quelled an uprising within his own party to end his campaign after a halting debate performance against Donald Trump.

A fifth House Democrat, Angie Craig of Minnesota, joined her colleagues on Saturday in calling for the president to step aside, as reports indicate more could follow soon.

In his rare primetime ABC News interview, Mr Biden dismissed his debate performance as just a “bad episode” and said only the "Lord Almighty" could convince him to end his bid for re-election.

Mr Biden is spending Saturday at his family home in Delaware before two public events on Sunday.

While no senior members of the party have called on the president to quit, the unease amongst Democrats is palpable.

Some polls show Trump's lead over Mr Biden widening, and many are concerned about losing the presidency and House seats, along with the Senate majority, if he leads the ticket.

On Saturday, congresswoman Craig, who is running in a competitive district in Minnesota, said she did not believe that the president could "effectively campaign and win against Donald Trump."

She said while she respects the president's decades of service, she is calling for Biden to step aside as the Democratic nominee.

“This is not a decision I’ve come to lightly, but there is simply too much at stake to risk a second Donald Trump presidency," she said in a statement.

Minutes after the ABC interview, Texas congressman Lloyd Doggett, the first House Democrat to call for Biden to drop out of the race, said on CNN that the "need for (Biden) to step aside is more urgent tonight than when I first called for it".

He said the longer it takes Mr Biden to make a decision to withdraw, the "more difficult for a new person to come on board who can defeat Donald Trump."

Other House Democrats including congressman Mike Quigley of Illinois and Seth Moulton of Massachusetts called on Mr Biden to withdraw from the race on Friday. They join Arizona lawmaker Raúl Grijalva who called for Biden to end his candidacy on Wednesday.

In his interview, Mr Biden declined to take a cognitive test and make the results public to prove he is fit to serve another term.

"I have a cognitive test every single day. Every day I have that test - everything I do [is a test]," he told George Stephanopoulos.

This response did not resonate well with Democratic congresswoman Judy Chu of California, who told news outlet Politico that his answer was “unsettling and not particularly convincing, so I will be watching closely every day to see how he is doing, especially in spontaneous situations".

Mr Biden's team is aware of pressure from within the Democratic Party to make a decision on the future of his candidacy within the next week, The Washington Post reported.

Reports emerged on Friday that House minority leader Hakeem Jeffries scheduled a Sunday meeting with senior House Democrats to discuss Mr Biden’s candidacy.

In the Senate, Senator Mark Warner of Virginia is attempting to form a group of fellow Democratic senators to ask Mr Biden to drop out of the race, according to reports from the Washington Post.

Mr Biden said he understood that Mr Warner "is the only one considering that" and that no one else had called for him to step down.

Massachusetts Governor Maura Healey, a Democrat, issued a statement urging the president to "carefully evaluate" whether he remains the Democratic nominee.

During the 22-minute primetime interview, Mr Biden rejected suggestions allies may ask him to stand aside, saying "it's not going to happen".

Mr Stephanopoulos pressed the president on his capacity to serve another term.

“I don’t think anybody’s more qualified to be president or win this race than me," Mr Biden said.

Mr Biden, who is due to speak at a rally in Pennsylvania on Sunday, thanked vice-president Kamala Harris for her support during the ABC News interview.

Ms Harris has emerged as a top contender to replace him if he were to step down.

While the rest of the country tuned in to Mr Biden's interview, Ms Harris was aboard Air Force Two, flying to New Orleans to attend the Essence Festival, an annual black cultural gathering.

Though Ms Harris has spent the last week sticking close to the president - flying from Los Angeles to attend the White House Fourth of July celebration and sitting in Mr Biden's meeting with governors as well as his call with Israeli Prime Minister Benjamin Netanyahu - aides contend it's business as usual for the vice-president.

On Saturday, she planned to sit for a moderated conversation at the Essence Festival in the first of a string of July events that appeared to target female black voters, a key constituency for Democrats in November.

Though the event is focused on black culture and celebrating diversity, questions around Mr Biden's candidacy and the potential for Ms Harris' ascension to the top of the ticket will be difficult to avoid.

As she continues her busy public schedule, Ms Harris has to maintain the delicate balancing act of projecting unequivocal support for her boss while also tacitly proving she's up for the job should Mr Biden's nomination unravel.

It's a tightrope she's walked over the last three years as Mr Biden's deputy, never appearing to overshadow the president or seeming too eager to take his place.