I wasn't offended. I was merely answering the question as to why ethnic minorities might be.
I contend that racism, prejudice, is an extreme form of tribalism - 'if you're not one of us, then you're one of them'. As in gangs.
When one is with a group of mates, of whatever ilk, banter is exchanged, often of a nature that would be deemed aggressive, threatening or demeaning, if used to a stranger. I've known racist people who have friends of the minority they choose to discriminate against, 'but he's ok, he's one of us'.
The thing about this type of humour is that it's seen by its purveyors as harmless. Non-malicious. But this very 'harmlessness' makes it acceptable to perceive, maybe unconsciously, that some people, or groups of people, are 'lesser', allowed to be laughed at.
But while the joker may make the odd joke, the 'victim' of said joke will have heard the like day in, day out, from loads of jokers. It's the reason why we hear of ginger-haired people committing suicide. It becomes the norm that these groups of people are laughed at and demeaned and makes it easier for those so inclined to take it further. It's insidious and all-pervasive.
That's some more stuff that I think.