He added: “They knew that he was in decline, and other people who monitored the White House knew that he was in decline, but all of them decided not to tell the American people.
“And the problem for Kamala Harris is, of course, she was there when all of this was going on, and already the Trump campaign are labelling her, trying to put her into the position of being one of the enablers of Joe Biden and one of the enablers of the myth that he was capable of carrying on.”
Trips and gaffes led to Biden’s downfall
Mr Biden’s downfall was triggered by a disastrous debate performance against Donald Trump on June 27, when he froze and lost his train of thought on national television.
The situation was worsened by more public gaffes at the Nato summit in Washington earlier this month when he confused Volodymyr Zelensky, the Ukrainian president, with Vladimir Putin, Russia’s leader.