Let’s leave sex and sexual relationships out of the picture. Let’s say that the amendment has passed and the Connecticut legislature has enacted a law granting some of the legal incidents of marriage to any couple. Under this law, a friend and you (or two friends and you) can co-sign each other’s loans, or whatever, if you choose this arrangement. (A thoughtful post by Justin Katz suggested this example to me—unfortunately, I can’t find the link right now.) Would the amendment bar this law? Or prevent a court from giving it effect? I don’t see how. The amendment’s wording suggests that states can, by statute, confer some of the legal incidents of marriage on unmarried couples (or groups); and that courts may construe statutes to confer those benefits.

Let’s take another example. The Michigan legislature decides to permit only married couples to co-sign each other’s loans. The state may have other sorts of domestic partnerships, but this isn’t part of the package. Under the amendment, the court may not construe the law reserving this benefit to married people (i.e., implicitly defining it as one of the legal incidents of marriage) as though it applied to unmarried people. That is to say: Whatever the state has decided, legislatively, to reserve to marriage, the courts may not extend beyond marriage. That leaves state legislatures with a lot of running room.

If one takes seriously the legal threat that the amendment’s supporters do—that without the amendment, the courts will impose same-sex marriage—the amendment leaves states with more running room than they’ll otherwise have.