Open question on our respective jockeying bases

At the moment, it seems like both parties are going through a bit of soul-searching as different elements of their respective bases jockey for position.

What does it say about the parties that the Republicans seem to be struggling with religion and governing philosophy (particularly with regard to immigration and taxes) while the Democrats seem to be struggling with race and to a lesser extent, sex?

Also, is winning either race a matter of stirring more resentment than your competitors? If so, and given this race's racial/sexual undertones, has this always been part and parcel to running a campaign or does 2008 represent a new low?