Over what age?
I'd say about 80% of the public could identify it with the Middle East, 70% as a form of religion, 60% as a branch of Islam, and maybe 30% explain the Sunni-Shi'ite conflict.
HAHA! Good one!
40% at most, probably less. Polls like this have been taken. They yield very depressing results.
I was going to say voting public, but in retrospect, you're right. Even that's generous.
I don't really have a good sample to judge this on, to be honest. I don't talk politics outside of any circle that is fairly well-educated (and neither do most people here) so I'm not exactly sure how we could know this in the first place.
EDIT: I make no damn sense today.