I don't know what text book you wrote or course you sat on at your Ivy League university, as you so modestly put it, but if you take yourself so seriously, why bother trying to understand British humour? SBC is making fun of self-styled liberals, like you and me, and by playing on crass stereotypes he exposes the hypocricy of liberals seeking to impose political correctness on everyone else. Whether he poses as a Jew, Kazakh, Japanese, Afro-American, Welshman, it doesn't matter to me. It's his interviewees' remarks and reactions that shock me, not his, which are merely to goad people on to saying things they wouldn't otherwise say in "politically correct" territory. Honestly, if you haven't worked that out, what's the use of going to university, even expensive Ivy League ones?
from the article: Report: Sacha Baron Cohen to retire alter-egos Borat and Ali G