Old people have always been in power. Take a look at all the presidents, congresspeople, generals, CEO's, and other leaders over time. All old, all of the time.
Take a look at the people who put the elected ones there. They aren't shouting "get off my lawn!". Until now.
It has nothing to do with size. Leadership skills generally take decades to develop, so leaders are always in the 45-65 age range
You should probably actually open a history book before making that absurd claim.
Apart from everyone in political power being old you mean?
Again, a very large group of people put them in political power. They respond to that large group of people in order to retain power.