President Joe Biden’s allies scrambled to contain the fallout on Friday from his faltering performance at the first 2024 US presidential debate after he struggled to stem a barrage of attacks and false claims from his Republican rival Donald Trump.

The Biden campaign had hoped that a strong debate would quell concerns among voters that the 81-year-old Democratic incumbent is too old to serve a second four-year term.

Instead, a hoarse Biden stumbled over his words and lost his train of thought at times, especially early in the debate.

One Biden donor, who asked for anonymity, called his performance “disqualifying” and predicted that some Democrats would revisit calls for Biden to step aside in favour of another candidate before the party’s national convention in August.

Panicking Democrats exchanged messages wondering whether Biden would consider stepping down.

One senior Democratic strategist said there would be calls for Biden to step down.

One such plea came from Thomas Friedman, the New York Times columnist who has the president’s ear, who called Biden a good man and a good president in an opinion piece early Friday.

But to stop Trump, he wrote, “the president has to come forward and declare that he will not be running for re-election.”

“It’s not likely to happen,” retorted Biden campaign co-chair Mitch Landrieu on CNN.

As the dust clears from the debate and with four months left before the election, he predicted Biden and Trump would be the nominees in November.

Josh Shapiro, the Democratic governor of Pennsylvania, urged Democrats to stop worrying and start working.

“Joe Biden had a bad debate, right, but Donald Trump was a bad president,” Shapiro said.

Interviews with undecided voters confirmed that it was a bad night for Biden.

They described his showing as feeble, embarrassing and difficult to watch.

Two White House officials said mid-debate that Biden had a cold, reflecting his aides’ anxiety about his performance.

Vice President Kamala Harris conceded that Biden had a “slow start” but argued that his record during his time as president outweighed one 90-minute event.

California Governor Gavin Newsom — who could be a leading Democratic alternative if Biden stepped aside — dismissed the notion that Biden could be replaced.

Trump, 78, has also faced questions about his fitness for office, given his conviction last month in New York for covering up hush money payments to a porn star, his efforts to overturn the 2020 election and his chaotic term in office.

But despite a litany of falsehoods from Trump during the debate, the focus in the aftermath was squarely on the incumbent.

Neither candidate is popular, and polls show many Americans are dissatisfied with their options. The country is deeply polarised, and a majority of voters have expressed concern that political violence could follow the election.

The debate at CNN headquarters in Atlanta took place far earlier in the campaign than any modern presidential debate, with more than four months — an eternity in US politics — before the November 5 election.

That could mitigate the damage for Biden, as the memory of his performance fades and news events generate fresh headlines.

Trump, for instance, is scheduled to be sentenced in New York on July 11, just days before his party convenes to formally nominate him. He still faces three other criminal indictments, though none appears likely to reach trial before November.

With opinion polls showing the race in a dead heat going into the debate, even a small shift could alter the campaign’s trajectory.

At a Waffle House restaurant in Atlanta in the wee hours on Friday, Biden stopped for food on his way back to the campaign trail, telling reporters, “I think we did well.”

Asked whether he had any concerns about his performance, he said, “No. It’s hard to debate a liar.”

Ben Rhodes, a deputy national security adviser to Democratic President Barack Obama, cautioned Democrats against playing down Biden’s performance.

“Telling people they didn’t see what they saw is not the way to respond to this,” he wrote in an X post.

Biden was headed for a Friday rally in Raleigh, North Carolina, a state that Democrats hope to win back from Republicans this November, before flying to New York for a fundraiser and the opening of a monument dedicated to the 1969 Stonewall riot for LGBT rights.

Trump will hold a rally on Friday in Virginia, a state he has lost twice but hopes to put into play in November.

Trading insults

The two candidates clashed on Thursday over the economy, abortion, immigration, the war in Ukraine and the Gaza bombardment in a debate that included some deeply personal attacks.

Trump unleashed numerous familiar false claims, including that the 2020 election was fraudulent, that Democrats support infanticide and that migrants have carried out a wave of violent crime.

He defended his supporters arrested for storming the US Capitol on January 6, 2021, refused to say whether he would accept this year’s election results and suggested he might prosecute Biden if he wins.

But Biden struggled to fact-check his predecessor in real-time, and CNN moderators Jake Tapper and Dana Bash did not correct Trump on air.

Biden landed some blows during the debate. He called Trump a felon and noted that the majority of Trump’s former Cabinet has declined to endorse his campaign.

“This guy has no sense of American democracy,” Biden said during a segment on the Jan 6 attack.

Biden also blamed Trump for enabling the elimination of a nationwide right to abortion by appointing conservatives to the US Supreme Court, an issue that has bedevilled Republicans since 2022.

On immigration, Trump’s strongest issue, the former president accused Biden of failing to secure the southern US border, ushering in scores of criminals.

But studies show immigrants do not commit crimes at a higher rate than native-born Americans.

The two candidates’ intense dislike for each other was in plain view throughout the debate, starting when they did not shake hands as they took the stage.

Biden called Trump a “whiner” and a “child” who, he said, cheated on his wife with a porn star and had the “morals of an alley cat.”

Trump said Biden was a “disaster” and a “Manchurian candidate” who favoured China over the United States. At one point, the debate devolved into a fight over which man had a better golf game.

The second and final debate in this year’s campaign is scheduled for September.