From a recent short posting by Steve Smith of the USD Law School:
Everyone favors equality: Everyone thinks that like cases should be treated alike. Nobody argues, “These groups are alike in all relevant respects, but they should be treated differently.” So when people disagree about legal or political issues, they aren’t arguing for and against equality. Instead, they are disagreeing about whether two cases, or two classes of people, actually are alike for the purposes of whatever is being discussed.
So the real disagreement is not about equality, but rather about what marriage is, or what it should be thought to include. Among the vast spectrum of human relationships, many of them valuable or ennobling, which ones should be classified under the heading of “marriage”? On that question, there are various views. Some think marriage is a relationship between one man and one woman. Some think it can include relationships between two committed adults, regardless of sex. Some would not limit marriage to only two persons. Some would not limit it to adults.
Reasonable people can debate these views in good faith and in various vocabularies—cultural, psychological, political, theological. So there are important debates to be had, and important decisions to be made. But the debates will only be cluttered up, and the decisions confounded, if the issue is framed in the question-begging terms of “marriage equality.”
Well said. And I would add that simplifying that which is not simple (human sexuality, for instance) does not make any group, in the long run, better off.