Democratic opposition to US President Joe Biden's re-election bid gained steam on Thursday as more members of Congress called on the 81-year-old to drop out of the race -- even before he mistakenly referred to Ukrainian President Volodymyr Zelenskiy as "President Putin."
"Ladies and gentlemen, President Putin," Biden said, referring to Zelenskiy before correcting himself.
The gaffe came shortly before a highly anticipated news conference where Biden hopes to ease fellow Democrats' fears that he no longer has the ability to beat Republican Donald Trump in the November election, or to carry on in the high-pressure job for another four-year term.
So far, 13 of the 213 Democrats in the House and one of the Senate's 51 Democrats have appealed publicly to the president to withdraw from the race.
During his solo news conference on Thursday evening, Biden will have to respond to questions on a wide range of topics -- including his fitness for another four years in the White House.
Biden's campaign has been on the ropes for two weeks, since his poor debate performance against Donald Trump, his 78-year-old Republican rival.
Presidential advisers who met with Senate Democrats on Thursday to try to drum up Biden's campaign argued that the debate has not dramatically shifted the race and said it would aim to win undecided voters by shifting the focus to Trump, a convicted felon who faces two more criminal prosecutions for trying to overturn his 2020 election loss.
Four more Democrats in the House of Representatives on Thursday called on him to end his campaign: Brad Schneider of Illinois, Greg Stanton of Arizona, Ed Case of Hawaii, and Hillary Scholten of Michigan.
"For our country's sake, it is time for the President to pass the torch to a new generation of leaders," Stanton said in a prepared statement.
Others stopped short of calling for Biden to drop out, even as they questioned his ability to lead the country.
"I doubt the President’s judgment about his health, his fitness to do the job, and whether he is the one making important decisions about our country, rather than unelected advisors," Representative Marie Gluesenkamp Perez said in a statement.
None of the party's leaders in Congress have called for Biden to end his candidacy, though former House Speaker Nancy Pelosi on Wednesday declined to say he should stay in the race.
Biden campaign chair Jen O'Malley Dillon and other top aides met with Senate Democrats to shore up support. Some said afterward they were still uncertain about his ability to win.
The campaign has commissioned a survey to test how Vice President Kamala Harris would fare if she were to replace Biden at the top of the ticket, according to a source with knowledge of the matter. A Reuters/Ipsos poll released last week found Harris would fare no better than Biden if she were the Democratic nominee, as both were statistically tied with Trump.
The New York Times reported that some longtime advisers were considering ways to convince him to drop his reelection bid, while NBC News reported that some campaign staffers thought he stood no chance of winning the election.