This is just a re-telling of a well known fact. Rural areas tend to be red and urban areas tend to be blue. Only this is retold with the connotation that republicans are somehow antisocial.

I'd just like to point out that proximity is not equivalent to interaction. In my experience social interaction was higher in rural settings. In a small town you will know all your neighbors, and probably half the people at your local stores. In a city it's the opposite, strangers abound.