President Biden faces a problem with no solution. No interview or speech will convince a doubtful public that he is still fit to serve. Perceptions of him had years to harden. In June 2020, 36 percent of voters said Biden was too old to serve. By 2024, that number had roughly doubled. In the Times/Siena poll conducted in February, 73 percent said he was “too old to be an effective president.” In the April poll, 69 percent said the same. In the June poll, 70 percent. After the debate, 74 percent.

The debate didn’t change what voters believed about Biden. The debate made it impossible for the Democratic Party to continue ignoring what voters already believed about Biden.

And make no mistake: They were ignoring it. After calling for Biden to step aside in February, I had a lot of conversations with top Democrats about Biden’s age. They universally knew it was a serious, perhaps lethal, political problem. So why didn’t they do anything? They thought the criticisms were unfair to Biden, who has been a good president; they thought the problem was unsolvable, because he would not step aside; they thought there were no other options; and above all, they thought Donald Trump’s malignancy would overwhelm fears of Biden’s infirmity.

They now know it won’t. In a post-debate Data for Progress poll, voters were asked which concerned them more: Biden’s age and physical and mental health or Trump’s criminal charges and threats to democracy. By 53 percent to 42 percent, they chose Biden’s age.

The Democratic Party is realizing it must act. But how? If Biden steps aside, it has two options: a coronation or a contest. In a coronation, Biden names Vice President Kamala Harris his successor and asks his delegates to throw their support to her. To some Democrats, this is the safest path. My newsroom colleagues Adam Nagourney and Jim Rutenberg report that “several Democrats said that no matter the risks, a new nominee could bring a host of benefits to the party, particularly if Mr. Biden anointed a successor in an effort to assure a smooth transition and minimize intraparty battling.”

But a coronation would repeat the mistakes that brought the party to crisis in the first place. What Democrats denied themselves over the past few years was information. If Biden had run in a competitive primary race, including debates, Democrats would have seen earlier how he’d perform. If Biden had routinely sat for extended, tough interviews and given news conferences, his shortcomings would’ve been clearer. In February, the special counsel’s report questioning Biden’s memory and cognitive capacity led to an extraordinary evening press conference in which Biden mixed up Mexico and Egypt, deepening the very doubts he’d meant to quell.