US Presidents and the relative age of their successors

When he takes office on January 20th, Joe Biden will become the oldest ever US President. And, assuming Donald Trump doesn’t rage quit the Oval Office before then, it’ll also mark the second time in a row a US President has handed over to a successor who’s older than them after Trump replaced the younger Obama in 2017.

That got me wondering about how different Presidents and their successors have been in age over the years. Because time remains stubbornly linear, and no one has yet lived to be the 289 years old they’d need to be older…