Today in my High School class my teacher was having a talk about diversity and said that she wasn't able to be racist because she was black. She claimed that racism can only occur when the racist person has societal power over the group or person that they are being racist towards. She also later claimed that racism is only when people take action to demean or lessen other groups of people, and since she was black she was unable to take action to demean white people? Is this true, or is she woefully misguided? (Just an FYI, she is also the diversity counselor for my entire school in addition to being my teacher)

Edit: just noticed the typo in the title. FML.