It's not yet clear how June's debate will affect President Biden's chances of reelection long term. But at least one expert says the president should stay in the race.

Scripps News spoke with Allan Lichtman, a distinguished professor of history at American University. His "Keys to the White House" model has correctly predicted 9 of the last 10 presidential elections — and by his formula, the debate didn't change the odds.

"We know debates have no predictive value. Hillary Clinton won all 3 debates and still lost. A lot of the same pundits who are claiming Biden is doomed were telling us that Trump was doomed after the Access Hollywood tapes," he said. "Not a single pundit or analyst who's claimed that Biden should drop out has a track record of predicting elections, and yet they claim they know what Democrats should do."

Lichtman says Democrats' only chance of winning is if President Biden is at the helm.

"Look what we've got with Biden staying in: He wins the incumbency key. He wins the contest key because he was uncontested. That means six of the remaining eleven would have to fall to predict his defeat. [If Democrats] bump Biden, they lose the incumbency key, they lose the contest key because there's no obvious heir apparent. So only four more keys would have to fall."

And even outside the framework of those keys, Lichtman says, replacing Biden with a new candidate could push the party into historical conditions that are difficult to overcome.

"That would create an open seat and an uncertain or contested nomination," Lichtman said. "Guess how many times since the turn of the century the White House party has won under those conditions. Never."

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