His poor performance was seen to confirm the assertion, frequently made by Trump, that Biden was too old and frail to serve a second term as president, and led directly to his decision to withdraw from the presidential race in less than one month later.

During the days and weeks following the debate, Biden and his campaign sought to reassure the Democratic Party and the general public that his performance was not representative of age-related decline.

On July 21, Biden formally withdrew from the race and immediately endorsed Vice President Kamala Harris to stand in his place as the party's presidential nominee, with Tim Walz replaced Harris herself as the party's vice presidential nominee; they would go on to lose to the Trump–Vance ticket in the general election.

[4][5] In April, most of the United States' major news organizations jointly drafted a letter to the Biden and Trump campaigns urging them to participate.

[10] On May 29, Kennedy filed a complaint with the Federal Election Commission alleging that the Biden and Trump campaigns colluded to prevent him from appearing at the debate.

[44] White House deputy chief of staff Bruce Reed collected material on policy contrasts with Trump.

[51] The decision was criticized by the White House Correspondents' Association, with its president Kelly O'Donnell stating that the lack of press access "diminishes a core principle of presidential coverage".

[54] Biden's stiff gait and body language throughout the debate was noted by observers,[55][56][57] as were his hoarse, weak voice[55] and his tendency to stare into the distance with his mouth open as Trump was speaking.

[58][59][60] Media sources also described him as frequently losing his train of thought and giving meandering answers, with many citing his "We finally beat Medicare" response to a question on the national debt as emblematic of this.

Four questions centered on the economy, four on democracy, three on foreign policy, two on immigration, two on abortion, and one each for climate change, age, opioids, race, and tax reform.

[67] Trump claimed that Biden supported the job growth of illegal immigrants,[68] defending his ten percent tariff,[69] and criticized the 2020–2021 U.S. troop withdrawal from Afghanistan.

"[74][75] At one point, Trump and Biden briefly had an argument over golfing abilities during a question regarding their fitness as president due to age.

[80] News organizations published articles after the debate documenting the truthfulness of the candidates' claims, finding that Trump made more exaggerated and false statements, while Biden had incorrectly cited information.

Many columnists, including from The Hill,[91] CNN,[92] Politico,[93] The New York Times,[94] USA Today,[95] Business Insider,[96] and Vox,[97] considered Trump the winner of the debate, although most noted his performance appeared acceptable only when contrasted with Biden's.

Columnists from MSNBC,[98] The Cook Political Report,[99] The Guardian,[100] and the Los Angeles Times argued that while Trump did not "win" the debate, Biden "clearly lost".

[104] Amy Walter, the editor of The Cook Political Report, said that while Biden's poor performance stunned "Democratic elite types", many voters had already "priced this in".

[99] According to Crowdtangle, "most of the top 10 most-liked posts on Instagram about the debate were either pretty neutral or emphasized how bad it was for both campaigns....And on TikTok, there was also a universal vibe that both candidates, not just Biden, were less than ideal for the moment.

[77][109] Several political analysts, including Susan Glasser,[84] Tim Miller[110] and Jeff Greenfield,[93] described it as the worst televised presidential debate ever, with Biden's weak performance overshadowing Trump's falsehoods.

[121] Several prominent Democrats, including former Presidents Barack Obama and Bill Clinton, initially rallied behind Biden, and resisted calls for him to step down due to one "bad debate.

[124] Democratic strategist Van Jones said that Biden had failed a test to restore the confidence of the country, and that the reaction for many supporters was "not just panic, it's pain".

[83] Former Democratic presidential candidate Julian Castro called the results of the debate "completely predictable", and that Biden failed to clear a very low bar by seeming unprepared, lost, and not strong enough to resist Trump's attacks or lies.

Tom Suozzi of New York even boarded an elevator going in the wrong direction to avoid being questioned, and another representative allegedly faked a phone call.

A small number of congressional representatives, notably Jared Huffman of California and Greg Landsman of Ohio, publicly said they were unsure whether Biden should continue to be the nominee.

Congressman Lloyd Doggett of Texas became the first Democrat in Congress to publicly call for Biden to step aside as the party's nominee.

He sent a letter to Congressional Democrats before Morning Joe explaining his decision, stating that "The question of how to move forward has been well-aired for over a week now.

[139] In an attempt to show voters and Democratic politicians that he was capable of facing Donald Trump in the 2024 election, he held a solo press conference on July 11, 2024, following the NATO 2024 Washington summit.

[141] On August 3, the Minnesota Star Tribune reported that Democratic Party presidential primary challenger Representative Dean Phillips said, “If people write anything, I just hope that they might write if [Biden] had debated me then and he had been on one stage, unscripted, with a national audience, and he demonstrated that decline then, this would have been very different circumstances.” He continued, “And that’s what I was trying to do.”[142] Chinese journalist and former Global Times editor Hu Xijin said the debate was "very entertaining for many Chinese people".