What I think it means is how in society, white males have always been dominant. White males have always dominated any other race/gender/etc. Black people, are of course criticized due to their skin color along with women because they're "weaker", thus "sit down-all the black girls" as if their opinion truly means nothing. It's a bit hard to explain, but I think he's kind of mocking how pathetic society is. Idk, that's what I got from it. I'm not sure if I just made any sense. XD