Why do people elect based on similarity rather than intelligence?

I don't understand the whole "have a beer with the candidate" thing. I've had a beer with plenty of people that I wouldn't want running the country. What I want in a president is someone who is capable of rational, calm thinking. I want someone who is intellectual and if that also makes the person an "elitist" I can handle that. We've seen what a dumb president can do. Why not try smarts for a change?