Karen Sellinger, left, and her partner, Bonnie Weissberg, of South Portland, reacts to a comment by Republican presidential candidate former President Donald Trump during the presidential debate with President Biden, during a watch party at Broadway Bowl in South Portland. Robert F. Bukaty/Associated Press

WASHINGTON — President Biden worked forcefully Friday to quell Democratic anxieties over his unsteady showing in his debate with former President Donald Trump, as elected members of his party closed ranks around him in an effort to shut down talk of replacing him atop the ticket.

Biden’s halting delivery and meandering comments, particularly early in the debate, fueled concerns from even members of his own party that at age 81 he’s not up for the task of leading the country for another four years. It created a crisis moment for Biden’s campaign and his presidency, as members of his party flirted with potential replacements, and donors and supporters couldn’t contain their concern about his showing against Trump.

Biden appeared to acknowledge the criticism during a rally in Raleigh, North Carolina, saying ”I don’t debate as well as I used to.” But he added, “I know how to do this job. I know how to get things done.” Speaking for 18 minutes, Biden appeared far more animated than he had the night before as he excoriated Trump for his “lies” and for waging a campaign aimed at “revenge and retribution.”

“The choice in this election is simple,” Biden said. “Donald Trump will destroy our democracy. I will defend it.”

He added, alluding to his candidacy, “When you get knocked down, you get back up.”

Even before the debate, Biden’s age had been a liability with voters, and Thursday night’s faceoff appeared to reinforce the public’s deep-seated concerns before perhaps the largest audience he will garner in the four months until Election Day.

Privately, his campaign worked to tamp down concerns and keep donors and surrogates on board. Democratic lawmakers on Friday acknowledged Biden’s poor showing, but tried to stop talk of replacing him as their standard-bearer, and instead shift the focus to Trump’s attacks and falsehoods.

“Well, the president didn’t have a good night, but neither did Donald Trump with lie after lie and his dark vision for America,” North Carolina Gov. Roy Cooper told The Associated Press on Friday, hours before he introduced the president in Raleigh. “We cannot send Donald Trump back to the White House. He’s an existential threat to our nation.”

In watch parties, bars, a bowling alley and other venues where people across the country gathered to tune in, Trump supporters, happily, and Biden supporters, in their angst if not dread, seemed to largely agree they had witnessed a lopsided showdown.

By the end of the 90-plus minutes, some Democrats were saying what partisans say to put the best face on things: It’s still early. One debate doesn’t necessarily sway the nation. Judge him by what he’s done and wants to do, not by how he says things.

Biden “just didn’t have the spark that we needed tonight,” Rosemarie DeAngelus, a Democrat from South Portland, said from her watch party at Broadway Bowl.

Former President Barack Obama backed up his former vice president, posting on X that “Bad debate nights happen.” Alluding to his own poor showing in the first debate of his reelection campaign in 2012, Obama continued, “Trust me, I know. But this election is still a choice between someone who has fought for ordinary folks his entire life and someone who only cares about himself.”

He added: “Last night didn’t change that, and it’s why so much is at stake in November.”

Lori Lahrmann left, and Tonya Morris, second from left, both from Cincinnati, watch the presidential debate between President Biden and Republican presidential candidate former President Donald Trump at Tillie’s Lounge on Thursday in Cincinnati. Both plan to vote for President Biden. Carolyn Kaster/Associated Press

House Democratic leader Hakeem Jeffries answered with a flat “no” when asked Friday if Biden should step aside.

Rep. Ritchie Torres, D-N.Y., allowed he “had to take a few more antidepressants than usual” after Biden’s debate showing.

But he added that “a Donald Trump presidency would cause me far greater discomfort than a Joe Biden debate performance.”

Biden’s campaign billed the Raleigh event as the largest yet rally of his reelection bid in the state Trump carried by the narrowest margin in 2020. He then traveled to New York for a weekend of big-dollar fundraisers that his campaign now needs more than ever.

Biden’s campaign announced that it raised $14 million on debate day and the morning after, while Trump’s campaign said it raised more than $8 million from the start of the debate through the end of the night.

Vice President Kamala Harris, whom the Biden campaign sent out to defend his performance, tried to reassure Biden supporters at a rally in Las Vegas on Friday, saying, “This race will not be decided by one night in June.

“This race will be decided by you. By us,” she said. “Who sits in the White House next year will be determined by what we together do in these next 130 days.”

Biden campaign communications director Michael Tyler said there had been no internal conversations “whatsoever” about Biden stepping aside, though he, too, acknowledged that the president had a “bad night” on stage.

Rep. Emanuel Cleaver, D-Mo., said he could hardly sleep because of the number of telephone calls he got after Biden performed “horribly” in the debate.

“People were just concerned. And I told everybody being concerned is healthy, overreacting is dangerous,” Cleaver said.

Rep. James Clyburn, a South Carolina Democrat whose support in that state helped Biden secure the Democratic nomination four years ago, said he would likely speak to Biden later Friday and his message would be simple: “Stay the course.”

Biden and his team have long wagered that voters would look past their concerns about his age and unpopularity when confronted at the ballot box with a choice between the president and Trump. Despite their concerns about Biden’s performance, they took solace in Trump doing little to expand his own appeal to voters on Thursday.

A patron puts their hand to their face as Republican presidential candidate former President Donald Trump speaks about how he would handle the Israel-Hamas war as people watch the presidential debate at Hula Hula, a tiki-themed karaoke bar on Thursday in Seattle. Lindsey Wasson/Associated Press

Polls from CNN and 538/Ipsos conducted soon after the debate found that most debate watchers thought Trump outperformed Biden. But the two men’s favorability ratings remained largely unchanged, just as they did in the aftermath of Trump’s conviction.

Democrats seized on Trump’s equivocations on whether he would accept the will of voters this time around, his refusal to condemn the rioters who stormed the Capitol on Jan. 6, 2021, trying to overturn his 2020 loss to Biden, and his embrace of the conservative-leaning Supreme Court’s overturning of Roe v. Wade that had legalized abortion nationwide.

But Biden fumbled on abortion rights, one of the most important issues for Democrats in this year’s election. He was unable to explain Roe v. Wade, the landmark Supreme Court ruling that legalized abortion nationwide. A conservative Supreme Court with three justices nominated by Trump overturned Roe two years ago.

As elected Democrats united behind Biden publicly, donors and party operatives shared panicked text messages and phone calls Thursday night and into Friday expressing their concern that Biden’s performance was so bad that he may be unelectable this fall.

Among the few public Democratic voices calling on Biden to step aside was congressional candidate Nancy Boyda in Kansas, who broke with most in her party and called on Biden to suspend his campaign and retire at the end of his current term.

But there were no immediate signs of organized efforts among donors, his campaign leadership or the Democratic National Committee to convince the president to step aside, according to interviews with several people who spoke on the condition of anonymity to share sensitive conversations.

Michigan Gov. Gretchen Whitmer, a Democrat frequently mentioned as a 2028 contender and speculated about as a potential replacement for Biden, released a statement backing him on Friday.

“The difference between Joe Biden’s vision for making sure everyone in America has a fair shot and Donald Trump’s dangerous, self-serving plans will only get sharper as we head toward November,” she said.

California Gov. Gavin Newsom also dismissed questions on whether he would consider stepping in for Biden, telling reporters, “I will never turn my back on him.”

Under current Democratic Party rules, it would be difficult, if not impossible, to replace Biden as the party’s nominee without his cooperation or without party officials being willing to rewrite the rules at the August national convention.

Trump was set to hold a rally Friday afternoon in Chesapeake, Virginia, a onetime battleground that has shifted toward Democrats in recent years but that his aides believe can flip toward the Republican in November.

Associated Press reporters Stephen Groves, Brian Slodysko, Colleen Long and Farnoush Amiri in Washington, D.C.; John Hanna in Topeka, Kansas; Gary D. Robertson in Raleigh; JJ Cooper in Las Vegas; Joey Cappelletti in Lansing, Mich.; and Bill Barrow in Atlanta contributed.