Why Do Such Elderly People Run America?

When Joe Biden climbed to the stage in California to celebrate his Super Tuesday comeback in the Democratic primary, three things happened in a matter of minutes. He basked in the thunderous applause from the crowd. He mistook his wife for his sister. And he delivered the sort of confusing, intermittently slurry, and occasionally indecipherable oration that has defined so many of his recent public appearances.

One might expect a typical opponent to seize on these verbal slips by questioning whether Biden, who is 77, is too old to hack it. But his rival Bernie Sanders, who has already suffered a heart attack during this campaign, is a year older. In January 2021, the three people most likely to be the next president—Biden, Sanders, and the incumbent, Donald Trump—would each be the oldest president to ever give an