Within the first half-hour of the presidential debate, I heard from three veteran Democratic presidential campaign officials, and all of them had the same reaction to President Biden’s performance: This is a disaster.

By the end of the debate, I was hearing a level of anxiety and alarm from those Democrats and several other party leaders and operatives that I’d never seen in 20 years of covering presidential politics. The discussion turned squarely to the need for the Democratic Party to replace Biden as the 2024 nominee, with four months to go to the election, and how to make that happen.

Could former President Barack Obama talk him out of the race? Could Chuck Schumer, the Senate majority leader and an old friend? Most of the Democrats agreed that only Jill Biden and the president’s family, and his longtime close aides, could get Biden to reconsider the race.

The Democratic panic was, on one level, a little shocking, given how much Donald Trump lied during Thursday’s debate and, more broadly, because of the threat that Trump poses to American democracy. Trump has already betrayed the Constitution, and Thursday night he wouldn’t promise to accept the 2024 election results and gave a weak answer about opposing political violence. He got worse as the debate went on, hurling unhinged attacks on Biden, even calling him a “Manchurian candidate.” His relative steadiness in the first 30 minutes started coming undone.

But the danger of a second Trump presidency is exactly what is fueling the panic. Democrats say Trump must be stopped. The Democratic nominee must stop him. And what we saw Thursday night was a Democratic president who could not effectively respond to Trump or deliver a memorable line — even when he rightly said of Trump, “Something snapped in you when you lost the last time.”

It wasn’t just that Biden wasn’t landing a glove on Trump on the economy, the overturning of Roe v. Wade, Covid, taxes, temperament or anything else that was coming up in the questioning. It was Biden’s voice (low and weak) and facial expression (frozen, mouth open, a few smirks) with answers that were rambling or vague or ended in confusion. He gave remarks about health care and abortion that didn’t make strong points, giving Trump a chance to say lines like, “I really don’t know what he said at the end of that sentence. I don’t think he knows what he said, either.”