Killing the patient

Yale Law School's Ernest Miller posted an interesting line of reasoning on why a constitutional amendment defining marriage could, in fact, open the door to end marriage as we know it:

Whether or not the [Federal Marriage Amendment] will permit states to have both heterosexual marriage and homosexual civic unions, there is strong case to be made that it will permit one-size-fits-all civic unions if the state abolishes civic "marriage."

After all, is there anything that requires a state to recognize the institution of marriage?

(Thanks to J.D. Lasica for the link.)