Carville and Greenberg focus-grouped a bunch of conservative republicans, and they determined that race did not motivate them.  These voters are, admittedly, conscious of being called racists, and say that if they disagree with Obama's policies, they fear being tagged with that label or are at least aware that they will be.  It's also clear that no amount of fact is going to penetrate their bubble.  These folks are hard-core.
At the risk of being accused of discounting evidence in front of my nose, I don't buy the absence of a substantial racial angle.  At all.  And, (shocker!) none of the voters admitted to harboring prejudices--just like that justice of the peace in Louisiana.  I simply don't trust the reliability of their research on something like this.  It's not as if the report surveyed their attitudes on other aspects of life or programs, and asked -why- they held particular positions.  It's been my experience that most people that harbor prejudices will simply deny having them, and then ask the black guy next to them how long they've been a janitor.  Most people who are really not will admit to thinking about race, and not being really sure whether certain beliefs are "right" or "wrong," but at least actively endeavor to figure that question out.  Given this focus group's makeup, it's just not convincing.  If Michelle Obama can't travel to SC because of security, something is seriously out of whack.
And I have to wonder about the angles of the authors.  Cui bono?  (I honestly don't know the answer to that).  *The above is rank speculation and should be regarded as such.  Comments welcomed.