What I found brave about Scorcese's script is that he has Tommy saying this line, when earlier in the film he was complaining about prejudice against Italians. "Can you imagine a Jewish broad being prejudiced against Italians...in this day and age?"
Scorsese was being ironic. And at the same time, showing the hypocrisy that most people are capable of (especially in the xenophobic world of the New York mob back then). I'm certain it was deliberate. Scorsese can subtly teach you something without preaching about it. That's a gift that can't be taught.
