McCain supports groups like the one in this Christian Science Monitor article, judging by the fact that he speaks at their conventions. Notice how good McCain had gotten at keeping quiet his conveniently timed outreach to the evangelical wing, and notice how he uses his wife to deliver the message (here she is discussing creationism with Katie Couric).
I had supported McCain (strongly!) because I wanted a moderate, Nixon-Reagan Republican candidate interested in market and country. Until this month I thought we had a chance of getting that. If you want an evangelical who puts Scripture first, he's your man.