None of our presidents were stupid. There's a difference from being an intelligent individual, as Obama very much is, and being a good president and politician. This extends outside to a number of other politicians as well, of course. For example, I never thought Romney was dumb, not a chance, but he didn't suit my preferences to be president.
He's not a genius though, that word shouldn't be thrown around lightly. Plenty of extremely intelligent folks aren't geniuses either.
Also, misspelling a word doesn't mean much of anything.