You're assuming that an average mind would be the most popular amongst an average group. That seems to be a huge leap to me. I would think that there are some barriers to entry when it comes to high-level politics that would slightly elevate median IQ scores (college degree at least, often a JD or MBA, extensive reading and writing, socioeconomic status). Wouldn't we usually have average-level presidents throughout history if this were true? Most speculation points to the conclusion that we have not.