About one-in-five felt 65 years old was time to hang up the teleprompter.

Elizabeth Warren is “only” 70, so she wouldn’t be deemed too old until her second term. If Hillary Clinton wins this time, she’d be 73.

In 2017, Trump was the oldest man ever to become president (70 years and 220 days), just ahead of Ronald Reagan (69 and 349 days).

If Biden or Sanders won, they’d be not only be the new oldest to take the oath but older than any other president ever leaving office.

On the other hand, if Pete Buttigieg, who’s 37, got permission from his parents, he’d be the youngest incoming president ever. Teddy Roosevelt (42 and 322 days) holds that title now, accidentally. He was vice president for William McKinley (54 and 34 days), who died from infection following a 1901 assassination attempt.

So, what would be an ideal age to take over the Oval Office?

Well, that same survey found that opinions averaged 48.

That would be almost precisely the age of Franklin Pierce (48 and 101 days). Don’t worry, no one else remembers him either.

That ideal age is about five years older than John F. Kennedy was (43 and 236 days), two years older than Bill Clinton was (46 and 154 days) and roughly eight months older than Trump’s predecessor (47 and 169).

Almost half (46 percent) of those surveyed felt the best age for an incoming president was between 35 and 45, while nine-out-of-ten thought the best range was 35 to 55.

George Washington (57 and 67 days) was both the oldest and youngest president ever. Actually, five of the first six presidents were 57 or 58.

Abraham Lincoln was 52 years and 20 days old. Ulysses Grant was 46 and 311 days. Jimmy Carter was 52 and 111 days. Now, he’s 95 and 63 days. George H.W. Bush was 64 and 222, while his son George W. Bush was 54 and 198.

Turns out, the median age of all the 45 incoming presidents so far was 55. Unless Kamala Harris (55 and 43 days) suddenly breaks out, that seems likely to change this time, most likely upward.