I’ll do it in 3
Jimmy Carter, born in 1924
William Taft died 1930 born 1857
Martin Van Buren died 1862, born 1782
Ok that doesn’t get you to 1776, but count it however you want.
Now when Jimmy Carter dies, then yes Trump would be the oldest living president (by about a month)
Also, holy crap, I didn’t realize hat Clinton, Bush II, and Trump were all born the same year. Weird bit of trivia for ya.