because people deteriorate mentally and physically with age.
It’s also factual that wealth greatly impacts education, but we wouldn’t want to suggest poor people are unfit for office due to this disadvantage right?
My parents are into their 70s and I have yet to detect even the slightest mental degradation.
It might be fair to say, as a sibling comment does, that one needs younger politicians so they can better represent one's constituents.
But to dismiss them just because they're old amounts to shutting off an economically productive segment of the population. More importantly, by discriminating against individuals because of their class membership rather than because of their abilities amounts to prejudice, no?