Key parts of Justice Scalia's dissent to the majority opinion on the Defense of Marriage Act (written by Justice Kennedy) are worth reading and pondering:
"...to defend traditional marriage is not to condemn, demean, or humiliate those who would prefer other arrangements, any more than to defend the Constitution of the United States is to condemn, demean, or humiliate other constitutions. To hurl such accusations so casually demeans this institution. In the majority's judgment, any resistance to its holding is beyond the pale of reasoned disagreement. To question its high-handed invalidation of a presumptively valid statute is to act (the majority is sure) with the purpose to "disparage," "injure," "degrade," "demean," and "humiliate" our fellow human beings, our fellow citizens, who are homo- sexual. All that, simply for supporting an Act that did no more than codify an aspect of marriage that had been unquestioned in our society for most of its existence— indeed, had been unquestioned in virtually all societies for virtually all of human history. It is one thing for a society to elect change; it is another for a court of law to impose change by adjudging those who oppose it hostes humani generis, enemies of the human race.
... In the majority's telling, this story is black-and-white: Hate your neighbor or come along with us. The truth is more complicated. It is hard to admit that one's political opponents are not monsters, especially in a struggle like this one, and the challenge in the end proves more than today's Court can handle. Too bad. A reminder that disagreement over something so fundamental as marriage can still be politically legitimate would have been a fit task for what in earlier times was called the judicial temperament. We might have covered ourselves with honor today, by promising all sides of this debate that it was theirs to settle and that we would respect their resolution. We might have let the People decide.
But that the majority will not do. Some will rejoice in today's decision, and some will despair at it; that is the nature of a controversy that matters so much to so many. But the Court has cheated both sides, robbing the winners of an honest victory, and the losers of the peace that comes from a fair defeat. We owed both of them better. I dissent."
Read his full opinion here as a PDF -- Justice Scalia's dissent begins on page 35.