I have been sitting, puzzling over the CNN exit poll that showed Hillary winning among people for whom either a) gender was an important factor in their vote, or b) race was an important factor in their vote.  Result a) is not surprising, given that women who want a female president will vote for Hillary.  But, typically, when race has been an important factor it has been African Americans who want to see an African American president.  This time the number was in the opposite direction, and the only plausible explanation is that the Clinton campaign has been race-baiting.
Personally, I blame it on Mark Penn more than on either of the Clintons themselves.  He was, after all, the one who originally wrote a memo comparing Obama in South Carolina to Jesse Jackson.  He also produced the "3am" ad that aired the weekend leading up to Texas and Ohio.  
There is something about that ad that doesn't sit right with me- and Mark Penn as producer is part of it.  But there is something unseemly about an ad, set in the home of a nice, white suburban family, that casts doubt about their safety in the hands of Barack Obama (i.e. the black guy).  It is subtle, and indeed subliminal.  But I think it gets at the heart of white, suburban, racial anxiety.  It prompts the [white] audience to think about the safety of their families at 3am, and who they want to protect them.  
The ad could have made its point in a million different ways, but it was obviously intended to invoke fear.  Initially people took it at face value (i.e. fear of an inexperienced leader), but I think it also tugs at the subliminal fear that suburban whites have when it comes to entrusting their family and property to a black man at 3am.