Well, I think the best way to classify this partivular kind of portmanteau religion/race prejudice is as a mutated variety of anti-semitism.

Calling it "sectarianism" doesn't really fit. After all, one in five Iraqis are Catholics, and a fair number of Palestinians are Christians as well, and I don't think this kind of insult is meant to exclude them.

Bigotry is maybe as good a term as any to cover all these kind of hang-ups.