One thing was clear by the end of the first 2024 presidential face-off: Democrats were in a panic following Biden’s halting debate night performance. Their consternation encompassed the halls of Congress, the moneyed coastal cities of donors, the party strongholds across the country and the bars and living rooms where Democratic stalwarts gathered to cheer on their guy.

Because Biden, 81, failed to deliver.

The president — who desperately needed to use Thursday night’s debate to reassure skeptical voters that he has the physical and mental stamina to lead the nation — instead offered a shaky performance, especially in the early minutes, when more voters were likely to be watching.

Perhaps more alarming for Democrats, Biden played into Trump’s caricature — of an enfeebled man past his prime — that has privately worried even some of Biden’s staunchest supporters.

His voice was soft and raspy, and he repeatedly tried, and failed, to clear his throat. His answers, at times, were rambling, and at one point he froze up. At another, he began an answer on abortion, before suddenly segueing into immigration. When Trump spoke, Biden often watched with his mouth agape and eyes flared wide — a split screen that gave off the impression of the aging grandfather that he is, not the swashbuckling leader he hoped to project.

Before the debate had even ended, and in the immediate aftermath, the concern pinged across social media and in private text messages.

On Capitol Hill, the panic among Democratic lawmakers and staffers was palpable, as they privately acknowledged that calls for Biden to step aside were only likely to grow as the party fully processed Biden’s dismal debate night performance. And across the states, operatives expressed similar concern.

“We’re so [f—ed],” texted one Democratic strategist in a battleground state. “He has great material. He just cannot deliver a single line.”

Julián Castro, the former Democratic mayor of San Antonio who served in Obama’s cabinet, called the debate “completely predictable.”

“Biden had a very low bar going into the debate and failed to clear even that bar,” Castro wrote on X. “He seemed unprepared, lost, and not strong enough to parry effectively with Trump, who lies constantly.”

Other Democrats were more blunt, calling on Biden to cede the nomination to a different — and presumably younger — Democratic leader before the debate had even ended.

Just an hour into the Thursday night’s CNN presidential debate, Andrew Yang — a 2020 Democratic presidential candidate — called on President Biden to step aside.

“Guys, the Dems should nominate someone else – before it’s too late. #swapJoeout,” Yang wrote on X after roughly an hour of watching Trump and Biden joust.

Around the same time, Nicholas Kristof — a New York Times columnist who tried unsuccessfully to run for governor in Oregon as a Democrat but was blocked from doing so because of a residency requirement — suggested that Biden’s debate performance should lead him to withdraw from the race and allow a younger contender to run.

“I wish Biden would reflect on this debate performance and then announce his decision to withdraw from the race, throwing the choice of Democratic nominee to the convention,” Kristof wrote on X, suggesting that someone like Sen. Sherrod Brown of Ohio, Commerce Secretary Gina Raimondo or Michigan Gov. Gretchen Whitmer “could still jump in and beat Trump.”

Inside the Biden campaign, officials conceded that the president struggled on the debate stage. They argued it took him some time to warm up and he improved as the night went on, but they also recognized that Biden damaged his candidacy on Thursday night.

Still, officials quickly moved to attacking Trump for his torrent of falsehoods and expressed frustration that CNN did not fact check the former president during the debate.

Biden’s stumbles, however, proved good for his rival, overshadowing a debate performance by Trump that was riddled with mistruths and grew more erratic as the evening went on.

In an interview with Vice President Harris, CNN anchor Anderson Cooper noted that some within the Democratic Party are wondering whether Biden should step aside — and asked Harris what she would say to that.

The vice president did not directly answer the question, instead arguing that Biden offered “a very clear contrast with Donald Trump on all the issues that matter to the American people.”

“Yes, there was a slow start, but it was a strong finish,” Harris said.

Leigh Ann Caldwell, Josh Dawsey, Amy Gardner, Colby Itkowitz, Meryl Kornfield, Tyler Pager, Maeve Reston, Marianna Sotomayor and Dylan Wells contributed to this report.