I'd say since Eisenhower and Goldwater. They've had a few good presidents including Arthur, T. Roosevelt, Coolidge, B. Harrison, Eisenhower, and McKinley. Goldwater in particular saw where the party was heading and warned vehemently about getting into bed with religious conservatives and running on morals issues. As he put it, I think every good Christian ought to kick [Moral Majority leader] Falwell right in the ass," and, "It's wonderful that we have so many religious people in our party, ... They need to leave their theologies in their churches. He also thought gays in the military was a non-issue, You don't have to be straight to be in the military; you just have to be able to shoot straight.
It took longer than expected, but it seems Goldwater is finally proving prescient.