It follows increasing clamour by Democrats against the 81-year-old US President’s bid to serve a second term after a bombshell report found he had “significant limitations in his memory”.
In a Justice Department investigation into Mr Biden’s handling of classified documents, special counsel Robert Hur found that he struggled to remember when he was vice president, or when his son died.
When the US President angrily defended himself on Thursday, saying his memory was “fine”, he erroneously confused Mexico and Egypt when talking about the Middle East.
It was not his first blunder last week. On Wednesday, he twice confused former German chancellor Angela Merkel for her predecessor Helmut Kohl when recounting a discussion during a G7 in 2021.
And that followed an earlier gaffe when he misremembered the name of French President Emmanuel Macron – instead referring to Francois Mitterrand.
Though the report was branded as “politically motivated” by Vice President Kamala Harris, polls are showing the President’s state of mind is becoming an increasing concern with voters.
In an NBC poll released on Tuesday – before the recent revelations – 76 percent of voters and 54 percent of Democrats said they had concerns about Mr Biden’s physical and mental health during a second term.
Dean Phillips, the only Democrat to stand against Mer Biden, warned: “Already facing the lowest approval number in modern history and losing in each of the key battleground states, this report has all but handed the 2024 election to Donald Trump if Joe Biden remains Democrat nominee – and I invite fellow Democrats to face the truth.”
One source with intimate knowledge of the Biden campaign told the Sunday Express: “This raises a number of questions as to what Jill Biden’s motivation is to keep her husband running. And she plays a huge part.
“She is calling the shots, is his closest confidante and caretaker. There are many who feel that Biden has played his part, performed his duty, and that he should be living his winter years in retirement in his mansion in Delaware. If she were to tell him it was time to step down, I think he would listen to her.”
Mr Biden’s blunders have played well for his 77-year-old Republican rival.
But he said that he was not sure whom to blame for the supposed disparity of justice. “I don’t know if it’s Biden,” Mr Trump said, “because I’m not sure he knows he’s alive.”
Earlier, he lashed out at a president who “can’t put two sentences together and he’s in charge of nuclear warfare”, and pledged: “World War 3 – it will never happen with me.”
If the election were held today, twice-impeached Mr Trump, who is viewed by many Democrats as an existential threat to American democracy, would be the clear favourite to win, leading Biden by two points in a one-on-one match and by five when independent candidate Robert F Kennedy Jr is included.
But Mr Trump’s fortunes could wane, worried Republicans revealed, if Mr Biden is dumped.
In her Friday message, Trump rival and former UN ambassador Nikki Haley said: “I have long said the first party to retire its 80-year-old candidate will win the White House.
“Democrats appear on their way to doing just that. Trump would get crushed by a Democrat with a pulse.”
Senior sources in the Republican party have told the Sunday Express they were braced for big changes.
“It is absolutely possible that we could have two new names on the Democrat ticket – this is being leaked by Democrats themselves,” said one.
“The DNC is in a critical situation. The big question is whether there will even be a debate after the primaries are over. How can you have someone who, in a legal document is said to have memory issues debating someone who doesn’t?
“I know that several high-profile Democrats have already said they have to dump Biden, and this will put even more pressure on them to revisit that decision.”
The very unpopular Ms Harris is only on the ticket, say Republicans, because the Democratic Party is “a party of identity politics” that needs to stem the haemorrhaging of African-American support.
But there is an alternative waiting in the wings who would represent a real challenge for Mr Trump.
“The only way to rectify this is to replace Harris with another black woman in the top spot. What other black woman is there with a great approval rating, name recognition and a link to a popular presidency in which Joe Biden also happened to serve as VP? Michelle Obama.”
Running mates could include California Governor Gavin Newsom or the popular Governor of Michigan Gretchen Whitmer.
“This is why many in the Republican party didn’t want Trump as a nominee,” said the source.
“He has been a weight on the ticket for three cycles and the only person he can feasibly beat is Joe Biden.
“If Biden goes, it may be over for Trump.”