No one, no individual or group, can show that they’re harmed by permitting gay men and women to marry, while those couples can easily show they’re harmed by prohibiting their marriage. You often hear arguments tossed out of the form “how does two men/women marrying hurt you?” as if that question is supposed to incline you to support or permit gay marriage based on a minimalist “it’s none of my business” ethic. And sometimes that feels a little unsatisfying, because “it doesn’t hurt anybody” is a pretty thin grounds for substantive acceptance and equality.
But that’s not what it’s for. In a very real sense, it’s about establishing whether or not someone has the right to speak for or against a legal decision. And that, ultimately, is how the law is shaped.