In a Staring Contest With Democratic Voters, Joe Biden Hasn’t Blinked

For years, President Biden has had a ready retort for the naysayers who have questioned his facility and fitness to run for president again at age 81 and to serve until he is 86. “Watch me,” he has said.

But in the days since tens of millions of Americans watched him fumble Thursday’s debate in real time, Mr. Biden has essentially adopted a new line: Trust me.

“Folks,” he said at a New York fund-raiser the next night, “I would not be running again if I did not believe with all of my heart and soul that I can do this job.”

It’s a cliché of political strategy that smart campaigns meet voters where they are. That typically means fashioning a strategy that taps into the public’s pre-existing feelings, rather than seeking to change how the electorate perceives matters.

Yet the trouble for the president is that even on the eve of his faltering debate, a New York Times/Siena College poll showed that 69 percent of voters — and 55 percent of Biden voters — saw Mr. Biden as too old to be an effective president. It is not a new concern: Nearly two years ago, a strong majority of Democratic voters said they wanted a new standard-bearer.

Now those persistent concerns from everyday Americans are being echoed publicly by many in the Democratic Party’s pundit class and privately by lawmakers, donors and strategists. They are worried about losing a 2024 campaign against former President Donald J. Trump, whom many view as an existential threat to the nation.

“Biden’s debate performance was a catastrophe from which there may be no recovery,” one House Democratic lawmaker texted a Democratic donor, Whitney Tilson. Mr. Tilson, a former hedge fund manager, shared the message on the condition the lawmaker not be named.

Around Mr. Biden, a siege mentality has set in for a team that remembers — and is fond of repeating — how it outlasted the doubters four years ago to win the nomination in the first place.

“He’s really at his best when the pundits are overreacting and counting him out,” Ted Kaufman, one of Mr. Biden’s closest advisers and his former chief of staff in the Senate, said in an interview. “He has a hell of record. I think he should stay. He is the best president in modern history.”

As the president huddled with his family at Camp David in recent days, his advisers rushed to keep in line any potential prominent wayward Democrats who might abandon their party’s leader. Mr. Biden’s team was discussing some kind of interview or news conference to comfort the concerned even before Mika Brzezinski, the co-host of the MSNBC show Mr. Biden often wakes up to watch, said in a monologue on Monday that “America needs an explanation from Joe Biden and reassurance that the other night was a onetime event.”

On Monday night, Mr. Biden returned to the White House and addressed a Supreme Court ruling on presidential immunity. He spoke for five minutes with the aid of a teleprompter and did not take questions.

This spring, Mr. Biden’s top brass pressed for the earliest general-election debate in history, as a way to force voters to sooner accept the reality of a Trump-Biden rematch that polls have repeatedly showed they do…