If this is an excerpt from a story, I wouldn’t be of much help. But from a layman's perspective, it seems like the character is attempting to please the failed humorist or he or she would have been frank. This in turn may have triggered a chain reaction, prompting the humorist to continue with his jokes which would have further affected the character. He or she is also giving the former a false sense of happiness and appreciation. This passage may not affect the whole story in a remarkably discernible manner, but it definitely proves the character's penchant for politeness. And that may be be a deciding factor in his or her further decisions that ultimately define the plot of the story.
I believe the answer is: italians take over and change white and black cultural traditions
The author make a reference on the migration of italian citizens to united states (mostly new york and chicago). The italian immigrants brought a mafia culture to united states which back than were in a fight for dominance for black and white culture.
