Outrage is big business now. That doesn't mean there is more tolerance. Some rap describes horrific acts of violence, but not because there is 'more tolerance' for that now than before. I think something else is working. I'll leave the explanation to the cultural experts here.
The Tucker/Rock stuff is not new, in my view. "In-tribe" humor of this sort is as old as anything. 30 years ago, the revolutionary 'Last Poets' made fun of welfare recipients. ("N-words are scared of revolution . . . ") It's the exposure of this stuff to outsiders that rings alarm bells.
mbs
How "acceptable" was Lenny Bruce thirty years ago? The man was put on trial for using obscenities. As for Mel Brooks, he has the most successful Broadway play right now. Put Eminem and "South Park" ontop of that, and you have a culture which can accept "outrage." Granted that there is also a very strong backlash, but I don't think we are less tolerant of such things than thirty years ago.
On the issue of what is acceptable within one's "tribe" -- there was an interesting essay in "The New Republic" about comedians Chris Tucker and Chris Rock. The writer noted that both of them use elements from minstrel shows in their acts such as high-pitched voices and bug-eyes. Let us not forget Rock's sneering attitude toward "n-words on welfare."
-- David