You have to be a minority or have a," culture", to understand it...
Sometimes it really is a ",(insert ethnicity of choice)-thing". Such as, have you ever been told it's a,"Black-thing you wouldn't understand"? For some races(or just people in general, but especially larger groups of them that have something in common; jocks, chearleaders, blacks, whites) in order to,"feel", superior to another they have to attempt to belittle others
!! If you think about it, it happens everyday. We make fun of antis, they make fun of us. The problems arise when people/races/clicks(sp?), cross the line of what is accepted by all as humorous(you have to be able to laugh at yourself) into judging people based on some preconception of the other persons affiliation. It could be race, political, sex affiliation, or even based on something simple as sports preference(male chearleaders catch hell)...
Now that I have stated the obvious, slavery is the one word answer
! WARNING SOAP BOX AHEAD!! Big surprise that the Black man is still being the but of the worlds jokes after somebody stole all their culture/language and religion, enslaved them, took away their men(by treating them like ,"BOYs" or property when they were more man than most, could you survive in Africa?) , and thus I come to my conclusion that the current,"Hip-hop culture" suburban America clash is all of their(the racist Whites of whom thankfully most are dead and gone) own making...
Take someones culture, language, and religion, away and then put them in a strange place together and see what happens, they make new ones that young White kids gravitate towards
... Karma, anyone?