The African American thing is interesting... I do know (from talking to a few professionals) that there are quite a few white men out there who like to be dominated by a black woman because of some form of racial guilt they have.

As for a submissive woman... Yes, interesting point. In my mind I think it is worth pointing out that women who were oppressed in the past had no choice in their lifestyle whereas modern women do. If you choose to be a slave you are not being hypocritical, merely exercising the right to choose.