Faced with questions about his mental acuity, Joe Biden, 81, said he would reassess his candidacy if he were diagnosed with a medical condition, as a Democratic Party heavyweight on Wednesday revived calls for him to withdraw from the White House race.
This is the first time Mr Biden has opened the door to the idea of abandoning his campaign.
Joe Biden tests positive for COVID-19
Asked Tuesday by BET media what might make him consider throwing in the towel, the presidential candidate replied: “If I had a medical problem that appeared, if someone, doctors came to see me and said: ‘you have such and such a problem’.”
Joe Biden has been playing for his political survival since his disastrous performance in his debate with Mr Trump, which sparked a wave of questions about his physical and mental abilities.
On Wednesday, California Rep. Adam Schiff urged Biden to “pass the torch,” saying he doubted the president could beat Donald Trump in November.
Mr. Schiff thus becomes the highest-ranking Democratic official to make the request publicly after the debate.
It is also the first to relaunch this call since the assassination attempt against Donald Trump during a campaign rally on Saturday.
Adam Schiff made his announcement shortly before the president made an effort to court Hispanic voters in Nevada.
Joe Biden “has been one of the most consequential presidents in our country’s history,” Schiff said in a statement to the Los Angeles Times.
“But our nation is at a crossroads,” he added.
“A second Trump presidency would undermine the very foundations of our democracy, and I have serious concerns about the president’s ability to defeat Donald Trump in November,” he added.
Virtual vote
Calls for the president to step down have been muted after the shooting of his Republican rival. Mr. Schiff’s statement ends that interlude.
About 20 House members and one senator have so far urged Joe Biden to throw in the towel.
Amid the tensions, Democratic Party officials announced Wednesday that they plan to speed up Mr. Biden’s nomination process with a virtual voting system, much to the chagrin of those hoping to see him drop out of the race.
The system would allow for virtual voting during the first week of August rather than waiting until the Democratic Convention, which begins in Chicago on August 19, when the candidate must be officially nominated for the November 5 presidential election against Donald Trump.
Some Democrats have sharply criticized the plan, saying it is a way to force through Biden’s candidacy despite doubts about his suitability and without discussing possible alternatives.
Elected officials plan to sign a letter to denounce it.
Vice President Kamala Harris is considered the favorite if Mr Biden steps down.
Democratic officials estimate the virtual campaign should be in place before the state of Ohio’s August 7 deadline for submitting candidate nominations.
Mr Biden says Democratic voters support him, but according to a recent poll, nearly two-thirds of them want the president to throw in the towel.