What a ridiculous analogy. There's a difference between accepting the support of someone and having someone as your pastor, spiritual mentor, and guide for twenty years. No one would expect Obama (or any politician) to vet the opinions of every supporter, but to claim that after twenty years Obama had "no idea" of Wright's character defies belief.
also, one expects religious leaders of one faith to make attacks against other religions. Jews and Christians do strongly disagree with each other.
But we don’t expect religious leaders to curse america and go after all white people and use vulgar language and accuse the US of creating AIDS