Today, a unanimous panel of the U.S. Court of Appeals for the First Circuit held unconstitutional a provision of the federal Defense of Marriage Act (DOMA) defining “marriage” exclusively as opposite-sex unions, setting up an all-but-certain Supreme Court case for next year.

Acting in response to a Hawaii Supreme Court decision stating that the Constitution may require that same-sex and opposite-sex unions be treated alike, in 1996 Congress passed DOMA, and President Bill Clinton signed it into law.  Remarkably brief by today’s standards, DOMA has only three sections:  Section 1 is the title.  Section 2 grants each state a plenary indulgence against being legally required to recognize a same-sex marriage recognized by another state.  Section 3—which the First Circuit addressed—defines the term “marriage” for purposes of federal law as meaning only opposite-sex unions.

It is rare for a circuit court to hold an act of Congress unconstitutional.  It is even rarer, however, for a case like that to end there.  The Supreme Court regularly decides to review any circuit court case holding a federal law unconstitutional.  In fact, at one time federal law required the Court to review such decisions.  The Court asked Congress to give it the discretion not to hear such cases, while also promising to review them whenever they may arise.  Congress agreed, and the Court has kept its part of the bargain.  The upshot is that this case is headed for the Supreme Court, the Court (almost certainly) will decide to review it, and the Court will issue its decision before it recesses for the summer in 2013.

Because this is America, where seemingly every public policy issue can be made into a legal one, litigation over the constitutionality of DOMA was inevitable.  That litigation has proved almost as controversial as DOMA itself.

Witness the Obama Administration’s initial decision to defend DOMA against constitutional attack, only later to abandon its defense of the law.  Witness the President’s efforts to square his stated belief that each state should be free to define a “marriage” however it wants with his decision not to defend DOMA.  And witness the decision of a law firm to represent a group of Republican House Members who sought to defend DOMA in place of the Justice Department, only later to see that firm drop that group as a client.  Even Stieg Larsson’s novels don’t have that many twists and turns.

In Massachusetts v. HHS,  the First Circuit Court of Appeals ruled that DOMA Section 3 violates equal protection principles implicit in the Due Process Clause (don’t ask; just keep reading) because it denies participants in same-sex unions the same federal benefits that participants in opposite-sex unions receive.  The court did not decide whether DOMA Section 2 is constitutional because the case did not raise that issue.  The bulk of the court’s detailed analysis in the 30-plus-page opinion is devoted to a discussion of one of three topics.

The first topic was the Supreme Court’s 1972 decision in Baker v. Nelson.  The Baker Court summarily rejected the plaintiffs’ claim – a claim that lies at the heart of this case and the entire same-sex vs. opposite-sex marriage debate – viz., that the Constitution requires the government to treat same-sex and opposite-sex unions alike.  Baker answered “No,” as the circuit court recognized.  If the Supreme Court’s Baker decision were applicable to this case, the circuit court acknowledged, that decision would compel the court to reject the plaintiffs’ challenge to DOMA.  Here, however, the circuit court found Baker inapplicable, carefully stepping around that decision like it was an IED in Iraq.  On to the second topic.

That topic involved other Supreme Court equal protection cases.  The circuit court meandered through 90 years of case law in the expressed hope of finding one decision that answered the question in this case, or at least told the circuit court how to answer that question.  The circuit court found no Supreme Court decision squarely on point.  By and large the court navigated around those other cases like it was avoiding shoals.  Again, the court came up empty-handed.

Finally, we come to the third topic, cases dealing with what lawyers call the appropriate “standard of review” that a court should use to decide whether DOMA is constitutional.  The question of what is the proper “standard of review” for a court to use when analyzing the constitutionality of a law seems to focus on how much deference a court should give to a legislature.

Actually, however, any standard of review discussion is less about how a court should review a law than it is about the nature and strength of the reason why the legislature passed it.  When a court reviews a law regulating the economic relationship between parties or between them and the government, the court all-but-reflexively upholds the act of the legislature.  By contrast, when a court reviews a law that discriminates against someone on the basis of race, the court is almost certain to strike down the act.

Courts treat differently a law fitting between those bookends.  Sometimes the legislature wins – e.g., Congress can require only men to register for the draft  – but sometimes it loses – e.g., Congress cannot deny “hippies” food stamps.  Most people, including many lawyers, would have better luck at the track than in court when challenging or defending a law in that No Man’s Land.

Just as Goldilocks found her third choice the best, so, too, did the circuit court.  It concluded that several of the Supreme Court’s decisions – Moreno (which denied hippies food stamps), City of Cleburne (which involved local discrimination against the mentally disabled), and Romer (which involved a provision in a state constitution prohibiting localities from treating homosexuals as a protected class) – required the circuit court carefully to scrutinize the reasons that Congress gave why the federal definition of marriage had to be limited to opposite-sex unions.

The court then did just that, and found those reasons insufficient.  In that regard, the court recognized that historically a legislature could regulate conduct, discriminate against it, or even outlaw it altogether simply because the legislature disapproved of that conduct on moral grounds.  Nonetheless, the circuit court stated that Supreme Court case law now deems moral disapproval of homosexual preferences an insufficient basis for discriminating against homosexuals, and the court found that the disparity in access to federal benefits resulting from DOMA’s definition operated in a discriminatory fashion.  The found it unnecessary to decide whether Congress was animated by hostility toward homosexuals or some other motive, because it found Congress’ stated justifications for DOMA inadequate in any event.

The one thing that is certain is that the debate over the definition of marriage in federal law won’t end with the circuit court’s decision.  A year from now (or thereabouts) the Supreme Court will have issued its own opinion on the subject, which should answer at least one of the legal issue raised by DOMA.  As for the policy issues:  That debate likely will continue well past the time that all nine Supreme Court Justices retire.