Democratic anxiety over President Joe Biden’s fitness to run for reelection broke out into the open Tuesday in a spike of panic as the first sitting member of Congress called on Biden to withdraw and a slew of other prominent officials who have backed the president vented their concerns.

One Democratic senator openly asked for assurances from the White House about Biden’s “condition” — “that this was a real anomaly, and not just the way he is these days,” said Sen. Sheldon Whitehouse of Rhode Island, who told a local television station he had been “horrified” by Biden’s performance.

Another Democratic senator, Peter Welch of Vermont, scolded the Biden campaign for “a dismissive attitude towards people who are raising questions for discussion.”

And later Tuesday, Rep. Lloyd Doggett of Texas, a veteran progressive lawmaker, issued a statement saying that Biden’s debate performance had disqualified him from running again.

“I had hoped that the debate would provide some momentum to change that. It did not,” Doggett said. “Instead of reassuring voters, the president failed to effectively defend his many accomplishments and expose Trump’s many lies.”

Biden’s fumbling, faltering debate performance Thursday set off a quiet panic among party officials and activists over whether he should be replaced on the ticket roughly four months before Election Day. But it also unleashed fresh anxiety among lawmakers, strategists and operatives about the effect of his stumbles on his party’s ability to win the critical races that will decide control of the House and Senate.

“He clearly has to understand,” Rep. Mike Quigley, D-Ill., said Tuesday on CNN, “that his decision not only impacts who is going to serve in the White House the next four years, but who is going to serve in the Senate, who is going to serve in the House, and it’s going to have implications for decades to come.”

To allay concerns, the White House announced Tuesday that Biden will meet with Democratic lawmakers and governors, sit for a network TV interview with ABC and hold a news conference in the coming days as he pushes back against growing pressure to step aside.

“We really want to turn the page on this,” White House press secretary Karine Jean-Pierre said of the intensifying calls for Biden to bow out of the race. She added that the 81-year-old president had no intention of stepping aside, characterizing his debate failings as simply evidence of “a bad night” when he had a cold.

Biden’s campaign also said Tuesday that it raised $264 million in the year’s second quarter together with the Democratic National Committee, an impressive haul that may help them calm fears within their own party. The total includes $127 million collected during June, when the campaign says it took in more than $33 million on the day of the debate and in its aftermath.

Meanwhile, former President Donald Trump’s campaign says it outraised Biden in the second quarter, with a reported haul of $331 million.

Democrats in congressional races across the country have long understood that they would need to outperform Biden in order to win their seats. In that sense, several Democratic operatives working on congressional races said, Biden’s performance would do little to affect the strategy in downballot elections. But the fresh injection of doubt over their party leader’s fitness to serve has confronted them with a new series of difficult calculations about their own races.

For now, leading Democrats are expressing strong backing for Biden. Sen. Chuck Schumer of New York, the majority leader, said during an appearance in Syracuse on Tuesday that, “yes,” he believed the president was fit to serve.

“I’m with Joe Biden,” he said.

But some are also conceding that the party has grave concerns about the situation. Rep. Nancy Pelosi, D-Calif., the former speaker, said it was “legitimate” to ask whether Biden’s bad night at the debate was a one-time flub or “a condition,” adding that Trump should have to answer the same question about the falsehoods he uttered.

But she conceded that she was hearing “mixed” feedback from Democratic donors on whether the president was up for running for another term in office.

“Some people are saying because Donald Trump is such an authoritarian and autocrat, we have to win this election,” she said. “This is not a normal election where you want to win, if you don’t, you cooperate and do the best you can for the country and hope to win the next time. This is something that is undermining our democracy. ... He cannot be president. Therefore, people are very concerned.”

Meanwhile, Tim Ryan, a former Ohio congressman, called on Democrats to replace Biden with Vice President Kamala Harris.

Ryan, in a Newsweek opinion column, wrote that he had lost confidence in Biden’s ability to defeat his rival after watching the president struggle in the debate with Trump.