Sure there are exceptions to the rule. But look at mac truck's map in post #148 and you'll see that it mostly divides between rural and urban with exceptions in both the North and the South.
In the South, politics is more likely to be polarized along racial lines. The whites belong to one party, the blacks to another.
You don't think that's true for the North also?
In the rural north, there are no minorities (except Indians), so whites vote more on the lines of economic interests. Unions were always a powerful force, especially in the mining, so that gave northern Michigan (along with Wisconsin and Minnesota) a Democratic heritage. But, yeah, they hate gays and gun-grabbers, so maybe a shift is coming.
Well, like I said there are exceptions, but usually cities wil be more liberal, and rural areas will be more conservative. The map in post #148 proves that well.