I know what you mean. The Presbyterian church I used to attend and one of the largest Methodist churches in my area both chartered busses to take members to the anti-war/Bush-bashing rally in DC a while back. The rally originated in the Episcopalian-run National Cathedral. The local Gannett paper ran an article the other week about how the major Protestant denominations in the area are suffering a major membership drain. Not a word was mentioned about how they’ve aligned themselves politically with the left, and how this might be contributing.
Not only that. They are losing a lot of members because people start to learn the Bible and realize that their church is actively going against it. So, one must leave. The Methodist church that I left can't figure out why people only hang around there for a few years then head off to another church (believing church). I think it's obvious.