I think it's more an issue of voting for one's self-interest, rather than say, voting for a particular race. It's why for instance, GOP Chair Michael Steele didn't win a senate race in Maryland over a white candidate.

It's not so much about voting for race, as much as it's voting for a candidate that is more likely to understand your experience and as a result, will be "thinking of you" as he or she makes decisions.

It explains why so few minorities (Specifically, blacks) have made it to the Senate since Reconstruction.