It seems that modern politics is running underneath most discussions concerning slavery. If blacks can own black slaves, it really amounts to nothing of importance to many since no modern day "sin" of racism is present. (I imagine whites owning white slaves falls in the same category.) But whites owning black slaves is pushed into a different category. Isn't racism a part of modern politics that should be left out of all discussions implied or not?
Racism consists of beliefs and behaviors under which one "race" of people is given, or should be given, rights, privileges, and opportunities that are denied to another race. That was certainly true in the beliefs and behaviors of many people in the 19th century. It is true that such beliefs were not universally seen in a pejorative fashion, versus today, where they usually are seen as pejorative.
The question was asked, is it significant that pre-Civil War free blacks owned slaves? The number of black slave owners was so small that it had no significant impact on the economic, political, or social environment of the 19th century that I can see, or that has been proven.