North Dakota's Constitution limits marriage to the union of one woman and one man. A North Dakota statute stipulates that same-sex marriages are not recognized in North Dakota. A man who has validly married another man in a state that recognizes such marriages moves to North Dakota and seeks to marry a woman in North Dakota. He applies for a marriage license, asserting that he is "single, never married." The county attorney requests advice from the state's Attorney General. In an opinion the Attorney General concludes that because North Dakota does not recognize same-sex marriages the man is unmarried and can legally aver that he is "single/never married" and can receive a license to marry a woman.
Is this opinion consistent with the US Constitution? First, if DOMA section 2, which permits states not to recognize same-sex marriages, is constitutional North Dakota is free to refuse to recognize foreign same-sex marriages. Section 2 is probably a valid exercise of Congress's power to enact laws that are "necessary and proper" to implementation of federal powers. Under United States v. Comstock Congress has "a large discretion as to the means that may be employed in executing a given power." Section 2 is a "modest addition" to prior statutes that have exercised the congressional power to specify the cirumstances under which the non-judicial acts of states must be recognized by other states. Section 2 does not limit state power, but is an accommodation of state interests. Finally, the link between section 2 and the Full Faith and Credit Clause is hardly attenuated. The Comstock factors point in the direction the validity of section 2.
If DOMA section 2 is not constitutional, the validity of North Dakota's position depends on the rationale for invalidating section 2. If section 2 is invalid because limiting marriage to opposite sex partners violates equal protection or substantive due process, North Dakota's position is untenable. But if section 2 is invalid because it exceeds federal power to implement the Full Faith and Credit clause, the question becomes whether North Dakota's application of its law to the status of a foreign same-sex marriage violates due process. Probably not, for North Dakota has adequate contacts with the new opposite sex marriage to apply its law to that marriage, and because the validity of that new marriage depends upon the status of the prior foreign marriage, North Dakota probably has sufficient governmental interests to merit application of ND law.
But consider the resulting mess. Abel and Cain (the men) are validly married in, say, Iowa , but Abel and Beatrice are validly married in North Dakota. Should Abel return to Iowa, Iowa must recognize his North Dakota marriage. Does this render Abel a bigamist under Iowa law? Probably. And suppose Cain remains in Iowa. After Windsor may he may file tax returns as married? What if Abel and Beatrice file a joint return as married; can Abel be married in two marriages simultaneously under federal tax law? I don't know the answers to the tax questions. I do know that these problems, while not likely to occur very frequently in this manner, are still likely to occur with enough frequency that the courts are going to be forced to make some additional law on Full Faith and Credit.