Well, in total fairness to the Reverend/Senator (or would it be Senator/Reverend?), a significant number of nominal "Christians" don't actually believe in Christianity per se.
Unitarians are a fine example. Warnock's "Social Gospel" crowd, which include Jim Wallis and Father Michael Pfleger (of Hillary mocking fame) are other fine examples of the "Jesus wasn't really God, or divine; he was just Super-Ghandi"... it fits well with Communism clad in Christian vestments and lends itself to Jesus being the ultimate community organizer.
Apparently many of these seeds are sown from the "Union Theological Seminary" here in New York, where Cornel West is currently teaching (I don't know if he's espousing a "healthy atheism" or something else).