Let me be clear that I have nothing against homosexuals, or any other group, promoting their agenda through normal democratic means. Social perceptions of sexual and other morality change over time, and every group has the right to persuade its fellow citizens that its view of such matters is the best.... I would no more require a State to criminalize homosexual acts – or, for that matter, display any moral disapprobation of them – than I would forbid it to do so....And by the way, Scalia has already committed to the proposition that Lawrence dictates the end of the exclusion of gay couples from legal marriage:
If moral disapprobation of homosexual conduct is “no legitimate state interest” for purposes of proscribing that conduct, and if, as the Court coos (casting aside all pretense of neutrality), “[w]hen sexuality finds overt expression in intimate conduct with another person, the conduct can be but one element in a personal bond that is more enduring,” what justification could there possibly be for denying the benefits of marriage to homosexual couples exercising “[t]he liberty protected by the Constitution”? Surely not the encouragement of procreation, since the sterile and the elderly are allowed to marry.The majority had claimed that Lawrence did not "involve” the issue of gay marriage, and Scalia said that could only make sense if you think "principle and logic have nothing to do with the decisions of this Court." (Of course, Scalia dissented in Lawrence and may decline to adhere to it, but it won't be because he thinks laws should enforce morality. It will be because he thinks courts should not strike down laws simply because there is no support for them other than morality.)
ADDED: Another post about Scalia, law, and morality, and I rather laboriously spell out some legal distinctions in the comments, here.