And by state, I mean a state under the constitutional law of Stephen Reinhardt.  Gawker has a story about a letter to an advice columnist whereby two fraternal twins (not just brothers) who have had an incestuous relationship since they were teens, and live together in a state where gay marriage is legal. (Gawker thinks the story is bogus; whatever, I’ll assume it is correct for con law purposes).

Now, assume these two brothers walk into city hall and apply for a marriage license. Reinhardt’s Constitution, the state cannot deny them a marriage license because they are a same sex couple. The clerk goes to the books, and says, marriage licenses cannot be given to incestuous couples. The couple files suit in federal court, with an as-applied and facial challenge to that statute, saying it violates the Equal Protection Clause and whatever else they find in the Constitution.

What happens? If the Prop 8 opinion means anything, what rational bases could the state proffer to justify a ban on consenting, adult incestuous relationships being recognized as marriage? I suppose the rationale about concern for genetic defects in offspring would be nugatory, as two men cannot naturally procreate. In fact, for the two of them reproduce, I think there would have to be a female involved (presumably, the female would be unrelated). Even there, the 9th Circuit more-or-less separated the notion of getting married from procreation, so reason is out. (So this would not prevent two female sisters from wedding).  I suppose another rationale could be based on some Judeo-Christian opposition to incest. Under the Constitution of Reinhardt, that is out too. What other rationales are there? Nothing but pure bigotry against these brothers who want the same recognition as everyone else.

Now, what would the Supreme Court say? Justice Scalia’s admonition in Lawrence v. Texas would come true.

State laws against bigamy, same-sex marriage, adult incest, prostitution, masturbation, adultery, fornication, bestiality, and obscenity are likewise sustainable only in light of Bowers’ validation of laws based on moral choices. Every single one of these laws is called into question by today’s decision; the Court makes no effort to cabin the scope of its decision to exclude them from its holding.

Next stop! Masturbation laws!

Update: A thought occurred to me. The case for same sex incestuous marriage is stronger than the case for opposite sex incestuous marriage, because the same sex couple would not be able to naturally produce children, which may be at a higher risk for genetic defect. Though, on some further reflection, the genetic defect rationale seems like bunk. For example many Ashkenazi jews are predisposed to certain genetic diseases, such as Tay Sachs. When two carriers procreate, the odds of having an affected child is quite high. This would seem to support a ban on these people from marrying and reproducing. Such a law would be laughed out of court. So it seems the only rationale against incestuous marriage would be moral dissaprobation of such a union based on norms of morality, which after Prop 8 cannot meet rational basis review.