Diest, Clarence Thomas is a good example. When he was going through the confirmation process, it was a very ugly, very ugly process, and he was accused of lots of things, one being he was an Uncle Tom for the simple fact that he was standing as an individual not as a black person per se. Remember, he wasn't black enough according to many black folks, and some of the people that skewered him the worst were of the black community. Republicans never accused Democrats of opposing the man because he was black. And the truth is it was all about politics.
In contrast, here we have Obama running as a black person, and those that don't vote for him have been accused of racism, and count on it - we will hear lots more about it. At the beginning, some black leaders claimed or debated whether he was "black enough," and the meaning of that could be debated as a subject in and of itself, but in order to gain the support of many in the black community, he had to prove he was "black," which apparently involves a whole lot more than skin color. Again, it is about politics, plain and simple, not color of skin.
By the way, I think the pictures show Clarence Thomas to have alot blacker skin than Obama.

On a serious note, Clarence Thomas has turned out to be one fine justice. I have heard him speak, and he speaks common sense, I like and respect the man a great deal, especially knowing what he has gone through to be an honorable individual to buck the poison thrown at him.
All of this is so plain as day, Democrats see people as groups, Republicans see people as individuals. This is a generalization, but I think a valid one, everyone is different, but in general, more Republicans think and act independently, than do Democrats or liberals. I will be skewered for this generalization I am sure.