One thing that has always baffled me about American Christians is how apathetic they are towards the environment.
At its core, I guess, the issue is that many are suckered by the right wingers and propaganda from large corporations to vote in their camp, by always bringing up other, more "pressing", moral issues.
I think as long as there are only 2 main viable parties to vote for, many of those folks will still vote along the traditional party lines.
So I agree with you, but it is an uphill battle.