Term limits wouldn't necessarily stop ancient people from being senators as some of them don't get that position until they're older, like Presidents.

It would help for Congresspeople, who do seem to start younger, but then there's the progression from Congress to Senate to President. Does the term limit reset at each level? So you can have two terms in each house then President? But two terms of Senate is already 12 years. By the time they get to the top of that ladder, they could still be older than you'd like.

Term limits for Supreme Court justices would be simple, at least. But some kind of cap is clearly well overdue.