Donald Trump is 72, Bernie Sanders is 77, and Joe Biden is 76. While most of us will be lucky to remember the URL to our favorite news site at that age (it’s splinternews.com, folks), many of the 2020 frontrunners hope to spend their golden years in the White House instead of in retirement.

But what effect does age play on the position of president? And how old is too old to assume the most powerful position in the world?