The dust has barely settled on last month’s historic health care ruling and already the next big constitutional battle over federalism has been teed up for the Roberts Court on the issue of same-sex marraige. At first blush the cases the court can consider on the issue of same-sex marraige may not seem to have much in common with the current frenzy of legal challenges to reproductive choice, but they do.

At the end of May a federal appeals court in Boston struck down the portion of the Defense of Marriage Act that bans married same-sex couples from receiving federal benefits on the grounds it is unconstitutional to treat some married couples differently from others. It was a reasonable take on constitutional protections that anyone other than the most hardened ideologues accept. And while the decision is largely grounded in equal protection jurisprudence, the opinion striking the federal benefits ban in DOMA contains just enough elements of federalism to it that given Chief Justice John Roberts’ decision in NFIB v. Sebelius, there’s plenty for equality advocates to see as positive in potential Supreme Court review.

But let’s not get excited just yet.

Indeed, just one day after the Roberts Court issued its historic ruling largely upholding the Affordable Care Act conservatives petitioned for Supreme Court review of Massachusetts v. Department of Health and Human Services. Of the various legal challenges to DOMA, this case raises the most concern of the possibility of Supreme Court shennanigans. That’s because this opinion found Section 3 of DOMA, which defines marriage for federal purposes as a union between a man and a woman an unconstitutional encroachment on the power to define marriage granted to the states by the Tenth Amendment.  

Unlike the federalism arguments in NFIB v. Sebelius, here the argument is that the states should have the power to dictate to the federal government what benefits flow to married couples and how those couples are defined. It’s like a mirror image of the argument made challenging the health care law which was the federal government lacked the power to compel states to expand Medicaid by making that expansion too financially beneficial to turn turn. The difference in framing is largely because marriage has traditionally been the province of state law and because in this case Massachusetts has its own law that defines marriage as a union of two consenting adults, regardless of gender.

Social issues don’t often get framed in the context of questions of pure federalism, but in this specific challenge to DOMA, they are. At the trial court level, trial judge, Joseph L. Tauro held Section 3 of DOMA overstepped Congress’s power to attach conditions to federal grants to states. For example, Judge Tauro wrote, the Department of Veterans Affairs had threatened to take back some $19 million from Massachusetts if it allowed the burial of a veteran’s same-sex spouse in a cemetery that had been built and maintained with federal money. Such “coercion” was constitutionally impermissible under basic notions of federalism and therefore, the trial court ruled, DOMA must fall.

On appeal the First Circuit dismissed the trial court’s embrace of the coercion theory, and at the time most legal scholars did not pay much attention to that portion of Judge Tauro’s holding. But that was well before all members, including the liberal wing of the court engaged in a lengthy consideration of the coercion theory during the challenge to the Affordable Care Act and used that theory to eventually limit the health care law’s Medicaid expansion along similar lines.

If the Roberts Court was willing to give states the ability to say “no” to the federal government when it came to Medicaid expansion by forbidding the federal government to make the states an offer they essentially couldn’t refuse, doesn’t it stand to reason that the Roberts Court will give the states a similar out in the DOMA cases?

Maybe.

A lot depends on the parallel case challenging California’s Proposition 8 that will likely come before the court at the same time as well as the fact that at least 31 states already have laws that define marriage as the union of one man and one woman. The Proposition 8 challenge seeks to establish a constitutional right to same-sex marriage, a specifically more ambitious goal than the DOMA challenges which simply seek to strike the federal law. If the court rules in favor of a right to same sex marriage then the issue of federal benefits is all but decided.

But should the court defer to the states on the issue of defining marriage, the DOMA challenge becomes much more interesting. Opponents of same-sex marriage may find themselves with a win on the issue of state’s rights in California, a loss in Massachusetts, and a battleground of future challenges that looks much like the reproductive rights landscape today.

The earliest the justices might decide to hear the case is in late September, with arguments made over the winter and a final decision in June.