On Tuesday, Lloyd Doggett of Texas became the first sitting Democrat to add his name to the pile of anonymous quotes from his colleagues about the commander-in-chief.
He said Mr Biden should make the “painful decision to withdraw”.
So far, only Mr Doggett has publicly called for Mr Biden to stand back, but plenty of Democrats make the same argument behind closed doors.
“Consider me a bedwetter,” one angry representative told Axios. “This is not getting better.”
The second camp of worried Democrats say Mr Biden has some time to recover from his TV performance, but think he should spend more time reassuring allies in the party before making a decision.
Those who are expected to go out and defend the president on a daily basis expect more contact from him at the most difficult time of the campaign so far.
The group includes JB Pritzker, the governor of Illinois, who convened a call with fellow Democrat governors on Monday to discuss the situation.
After hearing that most of the attendees had not spoken to the president, he arranged a meeting between Mr Biden and his allies at the White House on Wednesday night.
Nancy Pelosi, one of Mr Biden’s staunchest allies, said on Tuesday she had not spoken to him since the debate and argued that questions about his age were “legitimate”. Shortly after her interview on MSNBC, her office released a statement clarifying that she did not think he should stand down.