by Andrew Sullivan

About the author: Andrew Sullivan is the author of Virtually Normal: An Argument About Homosexuality and the former editor of the New Republic.

As with the military, [banning homosexual marriages] is a question of formal public discrimination, since only the state can grant and recognize marriage. If the military ban deals with the heart of what it means to be a citizen, marriage does even more so, since, in peace and war, it affects everyone. Marriage is not simply a private contract; it is a social and public recognition of a private commitment. As such, it is the highest public recognition of personal integrity. Denying it to homosexuals is the most public affront possible to their public equality.

This point may be the hardest for many heterosexuals to accept. Even those tolerant...