If we accept the premise that racism is about power then it follows that the question we should ask is not whether black people can be racist but whether or not there are any black people with enough power to be racist (or any white people with too little to meet the standard). Can a black CEO, mayor, or member of Congress be racist? If your average middle class white person not in a management position within his/her company with far less influence and power than any of these can be racist then it must follow that a black person in any of these positions (or just any management or other position of authority) can be racist.

Racists with power are, I think we can all agree, far more dangerous than racists with little to no power. Regardless, making the definition of racism logically incoherent at worst and utterly subjective at best only makes racist efforts to divide and conquer easier. It makes racism about subjective judgments about our relative power (real or perceived)rather than more objective measures such as the words that actually come out of our mouth or the way we treat other people. This is post modern moral relativism run amok and is especially tiresome when used as an argument to describe hateful ideologies like racism.