Let’s give him the benefit of the doubt, and assume that Biden senses [that he’s too old and frail to serve a second term, and that his age and frailty are driving voters to Trump], but he feels trapped by his own terrible vice-presidential choice. If he drops out and anoints Kamala Harris, she’s even more likely to lose to Donald Trump. But if he drops out and doesn’t endorse his own number two, he’d be … setting his party up for months of bloodletting and betrayal, a constant churn of personal and ideological drama.

There is no easy escape from these dilemmas. But the best approach available to Biden is a distinctively old-fashioned one. He should accept the necessity of drama and bloodletting but also condense it all into the format that was originally designed for handling intraparty competition: the Democratic National Convention.

That would mean not dropping out today or tomorrow or any day when party primaries are still proceeding. Instead Biden would continue accumulating pledged delegates, continue touting the improving economic numbers, continue attacking Donald Trump — until August and the convention, when he would shock the world by announcing his withdrawal from the race, decline to issue any endorsement, and invite the convention delegates to choose his replacement.

Pain would follow. But so would excitement and spectacle, the things that Biden himself seems too old to deliver. Meanwhile any agony would be much briefer than in a long primary battle … And the format would encourage the party-as-institution, not the party-as-mass-electorate, to do a party’s traditional job and choose the ticket with the most national appeal.

Ross Douthat, The Question Is Not If Biden Should Step Aside. It’s How.