I'm generally opposed to the concept of cultural appropriation. I'm Chicksaw, one of the so-called "civilized" tribes--so-called because of our zeal in appropriating European culture. As for costumes, if they're obviously meant to mock a racial group, they're offensive. I personally would have not problem if some white person showed up at a costume party dressed up like an Indian, unless it was obviously done to mock. Racism, unfortunately, is a human characteristic--not confined to any one race or group. It comes from the logical fallacy of over-generalization, and the human tendency to judge a book by its cover.
Declaring that you were a member in good standings with the local chapter of the Confederate White Knights of the Ku Klux Klan didn’t exactly endear you to the African American community.in your high school.
I think he means that blacks learned the lesson of violence, hatred, and cruelty, only too well from their former slave masters and oppressors, and we’re out for revenge – i.e. payback is a bitch. Which isn’t true but widely accepted in the white community.