BrendanB: John P, please correct me if I have misread your post but you seem to be equating involvement in politics with corruption.

Involvement, no. Buying politicians and laws, yes. But that's hardly something that religions are any more guilty of than any other large and wealthy organization. A religious organization that officially tries to get laws passed that are based on their religious beliefs is, I think, acting unconstitutionally. The Catholic Church (and others) should lose their tax-exempt status for doing so. Spending lots of money and using "moral" authority to make laws that codify bigotry, ignorance, poverty, and death is evil. The Catholic Church officially engages in this type of evil.