There's always been a double standard as far as criticism and making fun of an ethnic group go. People in that group have much more of a free rein to say things that peolpe outside the group could never say.
For instance, in a serious way (not even talking comedy routines now) Bill Cosby says things about rap and black culture that he takes a lot of heat for, but I doubt a white person could face the firestorm that they would be in if they said the same things.
Cosby Criticizes Black Youth