The party's leaders in the US Senate and House, Chuck Schumer and Hakeem Jeffries, said little about hours of closed-door talks among Democratic lawmakers on Tuesday, who in any event lack the authority to push the 81-year-old president aside even if they agreed on a course of action.
Biden's halting June 27 debate performance against Republican Donald Trump and low public approval have raised fresh doubts among some Democrats about his ability to win the November 5 election or to keep up with the demands of his gruelling job for another four-and-a-half years.
Representative Mikie Sherrill became the seventh House Democrat to call on Biden publicly to drop out of the race, saying in a statement, "The stakes are too high - and the threat is too real - to stay silent."
Many more have expressed worries that Biden has not done enough in the ensuing days to convince voters that the debate was an aberration, rather than a true reflection of his abilities.
But the president continues to argue that he is best positioned to defeat former President Trump, 78, whom he casts as a singular threat to American democracy.
Senate Majority Leader Schumer brushed off questions about Biden's fitness, saying three times, "I'm with Joe," during a brief exchange with reporters after Senate Democrats met over lunch to discuss the president's campaign.
House Minority Leader Jeffries, whose members huddled behind closed doors for nearly two hours to debate the path forward, told reporters that the meeting gave Democrats the chance to speak in a "candid and comprehensive fashion" and that the discussions would continue throughout the week.
Asked whether House Democrats were on the same page, Representative Steve Cohen replied as he exited the meeting: "We're not even in the same book."
"While President Biden has made clear he feels he is the best candidate to win this election, nothing that has happened over the past twelve days suggests that voters see things the same way," Representative Lori Trahan said in a statement on Tuesday. She said constituents in her Massachusetts district had raised questions about Biden's ability to beat Trump.
A Reuters/Ipsos poll last week found that one in three registered Democratic voters believed that Biden should quit the race, with 59% saying he is too old to work in government.
The poll also found that none of his possible replacements fared better in a matchup against Trump. The poll showed Biden and Trump tied at 40% each.
SWING-STATE SHIFT
While national public opinion polls offer a view of candidates' standing, US presidential elections are decided state by state. The nonpartisan Cook Political Report on Tuesday changed its ratings on three of the most competitive states - Arizona, Georgia and Nevada - to "lean Republican" from "toss-up," citing shifting voter views of Biden following the debate.
If Trump wins the White House and Republicans win majorities in both chambers of Congress, he will face few obstacles in pursuit of major policy changes. Democrats already face an uphill battle to protect their 51-49 Senate majority, as they must defend multiple seats in Republican-leaning states.
Republicans hold a 220-213 majority in the House.
Biden delivered a forceful speech to a gathering of NATO leaders in Washington on Tuesday, using the opportunity to demonstrate he can still serve as a global leader, while Vice President Kamala Harris - seen as the most likely candidate to replace Biden if he were to stand down - campaigned in Nevada.
"The one thing we know about Joe Biden is he is a fighter. He is the first to say when you get knocked down, you get back up," Harris told supporters in Las Vegas.
White House press secretary Karine Jean-Pierre faced another salvo of questions from reporters about Biden's health on Tuesday.
In a statement, the White House physician said Biden was not being treated for any neurological condition and had received a clean bill of health at his most recent physical examination in February.
Biden has secured renewed support from several key constituencies, including from members of the Congressional Black Caucus. Black voters make up a crucial component of the party's base.
Some House Democrats expressed frustration that the party was focused on Biden's shortcomings rather than unifying against Trump, who falsely claims that his 2020 loss was the result of fraud and has not committed to accepting this year's results if he loses.
"I think the president has decided that the discussion has come to an end and that he is firm in his commitment to run," Representative Stephen Lynch said of Biden, adding that the dissidents "are gonna have to get on board."