But unmistakably in a context of invoking a sense of collective responsibility for, and concern about, intra-community problems--as Rock himself says right at the beginning of that brief lampooning of 'broke-ass white people' you were singling out, "But we can't give a fuck about them--we just gotta do our own thing." Think of how many times in that clip he says, "I'm so damn tired of this shit...what the fuck is going on?" That's comically rhetorical, yes, but also dead serious. How often do you think you'll hear Jeff Foxworthy or Ron White going beyond laughing about 'rednecks' to actually appealing to a collective white sense of responsibility for their comic target's social ills? They don't have to, because white people aren't in the position of having to prove to anyone that we aren't typified as a group by criminals and the permanent underclass. The very term "white trash" implies that's it's taken for granted that the 'non-disposable,' i.e. normal, variety of white person is reliably a fine, upstanding sort. Rock's contempt, if that's really the right word, for "niggers" isn't at all the easily afforded variety--the joke sticks in the throat, and that's precisely what charges it up and therefore makes it so funny, in the way that only something which carries these kinds of risks to the one making the joke (and their primary audience) can be.