Biden assures campaign donors he can still win election

Mr Biden’s performance was not only criticised by those in politics.

A prominent editorial in the New York Times described his determination to run again as a “reckless gamble”.

It said Democrats should “acknowledge that Mr Biden can’t continue his race, and create a process to select someone more capable to stand in his place”.

Voters across the United States have also expressed concerns over voting for either candidate following Thursday’s debate.

Long-time Democrat Lori Gregory told the BBC that she “could not handle” watching the debate, and asked, “is this the best our country can do?”

Republican Crystal Myers-Barber said it was “painful to watch”, but added that she thought “Trump came across very level-headed and presidential and Biden came across very weak.”

Democrat Shana Ziolko said she was “frustrated” watching the debate, and thought there was no clear winner.

A post-debate poll by liberal pollster Data for Progress found that 62% of likely voters who watched or read about the debate found Trump won. Only 30% of those polled said Mr Biden won the debate.

Until further polling is conducted, fundraising could be another indication of continued enthusiasm for Mr Biden’s candidacy.

In a memo, chairwoman Jennifer O’Malley Dillon said the campaign raised more than $27m (£21.3m) from the Thursday debate to Friday evening.

“Following Thursday night’s debate, the beltway class is counting Joe Biden out. The data in the battleground states, though, tells a different story,” she said.

“This election was incredibly close before Thursday, and by every metric we’ve seen since, it remains just as close”, she added.