Biden's actions have been criticized not only in political circles.
A prominent New York Times editorial called his decision to run again a “reckless gamble” and urged him to do some soul-searching this weekend.
Democrats said they “must recognize that Mr. Biden cannot continue to compete and create a process to select someone more competent to take his place.”
Following Thursday's debate, voters across the U.S. also expressed concerns about which of the two candidates they would vote for.
Rep. Rory Gregory, a longtime Democrat, said in an interview with the BBC that he was unable to watch the debate and asked, “Is this the best our country can do?”
Republican Crystal Myers-Barber said it was “painful to watch,” but added, “Trump has been very level-headed and has taken on the presidency, and Biden has looked very weak.”
Shanna Giolko, a Democrat, said she was “disappointed” watching the debate and thought there was no clear winner.
A post-debate poll conducted by progressive polling firm Data for Progress found that 62% of voters who watched or read the debate said Trump won. Only 30% of those surveyed said Mr. Biden won the debate.
Until further polls are conducted, the fundraising could be further evidence of continued enthusiasm for Mr. Biden's nomination.
The campaign had raised more than $27 million (£21.3 million) from Thursday's debate through Friday evening, chairwoman Jennifer O'Malley Dillon said in a memo.
“After Thursday night’s debate, the Beltway establishment is counting on Joe Biden, but the data from key states tells a different story,” she said.
“This election was incredibly close before Thursday, and by every indicator we’ve seen since then, it’s still close,” she added.
