As for the topic, it's stupid yes, but it brings up a good point. I don't think Obama will play well in middle America. He just came out in favor of sex ed for Kindergartners. I don't have a probelm with this, but I can't imagine that's going to play well to families in this country. I think Hillary will portray herself as possesing "heartland values" and will win the nomination and likely the presidency.
People in middle America aren't mostly anti-Harry Potter nutjobs, and I think it's safe to say that people who would not vote for Obama on the basis of being a Harry Potter fan aren't going to be voting for any Democrat.
You seem to have missed his point... but it's not the Midwest that gets upset over mentions of sex (at least, not the parts of the Midwest that consider voting for Democrats). It's the suburbs, especially newly developed sprawling suburbs in places like Florida, Georgia, and California. (None of those states are particularly likely to be relevant in the general election, but that's not so important.)