Now, in the greatest crisis of his career, he’s falling back on his ingrained instincts, his desperate desire to prove himself. But at the moment, given the stakes, his instincts feel less redemptive than delusional. Rather than bowing to the reality of his humiliation, he is doing everything in his capacity to resist it, even if hardly any sane political analyst shares his faith in his ability to recover—even if there’s no reversing the screamingly obvious biological facts of aging.

If his aides and fellow politicians want to help him back away from this disaster, they need to understand his temperament. When they have conversations with Biden about his future, they must respect his dignity, and acknowledge his extraordinary achievements. But the truth can’t be painted over. A man who will do whatever it takes to escape humiliation needs to understand that suffering the near-term indignity of stepping down will allow him to avoid the long-term indignity of being remembered as one of history’s great fools. To prove the doubters wrong, he needs to summon sufficient grit one last time—and relinquish the nomination.