The "best and the brightest" don't have the money to run. You practically have to be a millionaire in order to get into office. Even then your entire life is put under a microscope and even the slightest misdeed can cause you to lose (He smoked a joint when he was 15! Sure sign he's an drug addict!).
I don't mean any offence, but being rich doesn't mean one is all that smart. Although I'm sure there are many wealthy folks who are intelligent, they're just not in politics (they're too smart for that).