Joe Biden has warned donors that Donald Trump will try to "indirectly steal" the 2020 election by making a case against mail-in ballots, a voting method that many are expected to use to avoid exposure to the coronavirus during November's US vote.
The presumptive Democratic presidential nominee asked donors attending a virtual event to spread the word that "this president is going to try to indirectly steal the election by arguing that mail-in ballots don't work".
Mr Trump will present mail-in ballots as fraud by making the argument that "they're not real, they're not fair", said Mr Biden.
On 'The Daily Show With Trevor Noah' in June, Mr Biden had warned that Mr Trump might "try to steal" the election. He has said Mr Trump might try to delay the election and might not leave the White House voluntarily if he loses.
Mr Biden's remarks offered the most detail about how he believes Mr Trump might unfairly influence the contest's outcome. Mr Biden's campaign has mounted an aggressive voter-access effort, including hiring a team of lawyers to challenge any irregularities.
They come as Mr Trump in recent weeks has stepped up his rhetoric about the veracity of mail-in voting. At an event last month in Arizona, the US president suggested without evidence that the method presents an opportunity for fraud.
"Where are they going? Where are these ballots going? Who's getting them? Who is not getting them? A little section that's Republican," Mr Trump said, speaking specifically about California's vote-by-mail system.
"Will they be stolen from mailboxes as they get put in by the mailman? Will they be taken from the mailmen and the mailwomen? Will they be forged? Who is signing them? Who's signing them? What, are they signed on the kitchen table and sent in? Will they be counterfeited by groups inside our nation?"
Mr Trump added: "Will they be counterfeited, maybe by the millions, by foreign powers who don't want to see Trump win?"
Matthew Morgan, the general counsel to the Trump campaign, accused Mr Biden of sowing fear.
"Joe Biden is fearmongering and purposely misleading American voters," said Mr Morgan said. "The only people trying to fundamentally change the way we vote and make our election system less secure are Democrats."
Meanwhile Mr Trump has attempted to make dementia an issue in the campaign during a TV interview.
His phrase "Person. Woman. Man. Camera. TV." got an unlikely moment in the spotlight. The president (74) was attempting to demonstrate his mental fitness by reciting five words, in order over and over in a television interview.
He said the collection of nouns was part of a cognitive test he had aced while declaring that his likely Democratic opponent, Joe Biden (77), could not do the same.
The Trump campaign has long tried to paint Mr Biden as having lost some of his mental sharpness.
But the gambit has yet to prove successful in denting the former vice president's standing in the race.
That leaves Mr Trump trying to escalate the attacks while defending his own ability to handle the mental rigours of the job.
On Fox News Mr Trump boasted of having "a good memory, because I'm cognitively there". But he said: "Now Joe should take that test because something's going on." (© The Washington Post)