Matt quotes my colleague Ken Sherrill about why Democrats who support equal rights may be reluctant to disclaim the notion that homosexuality is immoral. The other important point, I think, is that from a political (as opposed to personal) level, what matters is the policy, not the subjective morality. Just as it doesn’t matter what John McCain “really” thinks about abortion when he’s resolutely in favor of criminalizing it, if you support gay rights your personal position about the morality of gay sexuality is not terribly important.
…Pithlord, Matt and lt are correct to point out in comments that it’s wrong to imply that public comments about the morality of sexuality are irrelevant. Obviously, it’s suboptimal for candidates to express the wrong opinion on the issue.