Why aren't smart people elected?

Instead of relying on charisma, why not have Presidents based on intelligence and knowledge?  Someone who has a masters or professional degrees, has written papers and books, and is just a really knowledgeable guy?  Rather than, um, someone who's not.

>> 15
Preaching to quire, you misunderstood what I meant.
I meant that "The Internets" probably doesn't appreciate being told that the smartest president the US ever had went pretty conservative.