Ethnic slurs are a method of disparagement sometimes used for differing purpose. They seem to me to say more about the speaker than the target. An attempt to make something OK that isn't; It's OK for them to be slaves, they are less than human. It's OK to go off to war and kill them, they are less than human. This one came into play as I was staging to go to Vietnam. Interestingly, many black men had no problem with the use of the word gook. They used the word for the same reasons the white guys used it.

On a smaller scale, various forms of discrimination because they aren't one of us. The woman with a complaint becomes a bitch. The same theme is in play with dehumanizing political partisanship where the bad tribe is no longer about race but opposing views. All about making some behavior that is harmful OK in the mind of the speaker. The harm is not so much in the words but the attitudes and actions of the speaker that lead to their use. People using that language are telling you more about themselves than about the target of their scorn.

When my children encountered racial slurs, I told them my story of the turd. "If someone tries to give you a turd and you don't take it, they are the one with the dirty hand, not you."