A fumbling performance, and a panicking party

Supporters line up to see President Joe Biden after the CNN presidential debate Thursday in Atlanta, Ga. (Haiyun Jiang/The New York Times)

President Joe Biden and first lady Jill Biden arrive at a campaign event after the CNN presidential debate with former President Donald Trump Thursday in Atlanta, Ga. (Haiyun Jiang/The New York Times)

A voter at a debate watch party put on by the Democratic Party of Orange County, at a church in Laguna Beach, Calif., on June 27, 2024. Biden left the CNN studio in Atlanta facing a referendum on himself and his capacity that will reverberate for days if not longer. (Maggie Shannon/The New York Times)

President Joe Biden speaks during the first 2024 presidential election debate with former President Donald Trump at CNN's headquarters in Atlanta, on Thursday, June 27, 2024. Biden left the debate facing a referendum on himself and his capacity that will reverberate for days if not longer. (Kenny Holston/The New York Times)

Former President Donald Trump and President Joe Biden listen to the moderators during the first 2024 presidential election debate at CNN's headquarters in Atlanta on Thursday, June 27, 2024. (Kenny Holston/The New York Times)

President Joe Biden hoped to build fresh momentum for his reelection bid by agreeing to debate nearly two months before he is to be formally nominated. Instead, his halting and disjointed performance Thursday night prompted a wave of panic among Democrats and reopened discussion of whether he should be the nominee at all.