Opinion | To Serve His Country, President Biden Should Leave the Race

President Biden has repeatedly and rightfully described the stakes in this November’s presidential election as nothing less than the future of American democracy.

Donald Trump has proved himself to be a significant jeopardy to that democracy — an erratic and self-interested figure unworthy of the public trust. He systematically attempted to undermine the integrity of elections. His supporters have described, publicly, a 2025 agenda that would give him the power to carry out the most extreme of his promises and threats. If he is returned to office, he has vowed to be a different kind of president, unrestrained by the checks on power built into the American political system.

Mr. Biden has said that he is the candidate with the best chance of taking on this threat of tyranny and defeating it. His argument rests largely on the fact that he beat Mr. Trump in 2020. That is no longer a sufficient rationale for why Mr. Biden should be the Democratic nominee this year.

At Thursday’s debate, the president needed to convince the American public that he was equal to the formidable demands of the office he is seeking to hold for another term. Voters, however, cannot be expected to ignore what was instead plain to see: Mr. Biden is not the man he was four years ago.

The president appeared on Thursday night as the shadow of a great public servant. He struggled to explain what he would accomplish in a second term. He struggled to respond to Mr. Trump’s provocations. He struggled to hold Mr. Trump accountable for his lies, his failures and his chilling plans. More than once, he struggled to make it to the end of a sentence.

Mr. Biden has been an admirable president. Under his leadership, the nation has prospered and begun to address a range of long-term challenges, and the wounds ripped open by Mr. Trump have begun to heal. But the greatest public service Mr. Biden can now perform is to announce that he will not continue to run for re-election.