Gonna be interesting to read Kennedy's opinion on that issue when DOMA's overturned (I'm guessing he'll be given the duty).
I'm not certain it will be overturned. It could be, but I don't see Kennedy as being a sure vote for overturning. It's also possible that it'll be a decision that narrowly strips the Federal government of the power of deciding what a marriage is and leaves the larger issue of whether there is a constitutional right to same-sex marriage for another day.
What you describe is a wholesale overturning of DOMA (or at least sec. 3, which is all that's at issue), so I'm not sure what your point is.
Also, the court cannot decide Windsor by rejecting a constitutional right to same-sex marriage as that would not answer the question of whether Congress has power to enact DOMA. (The case could be resolved by declaring that the constitution guarantees same-sex marriage, making DOMA clearly unconstitutional, but as that would go beyond the briefs in the case and the holdings of the Circuits, I doubt the court would go there.)
In the Obamacare case, Roberts pretty much shattered the need for his court to consider just arguments raised by the briefs and arguments.
That's not true at all. The tax issue was heavily briefed by both sides. It was seen as a secondary argument that the government was unlikely to win, but it was heavily briefed.
But they don't have to rule that the federal government must use state definitions for everything, either. (A truly bizarre argument that even the DOMA defenders aren't making.) That's not what the Circuits did; they didn't say the federal government must always defer to state definitions on anything other than marriage. And the reasoning on that is pretty sound, though of course it would be a case-by-case inquiry on when the government must defer (but the number of potentially disputed circumstances are quite small--just marriage right now).
^ This. It should actually be pretty easy for the court to strike down DOMA without
necessarily finding a constitutional right to same-sex marriage. The federal government doesn't actually marry anyone; it's the states that grant marriage licenses to couples. The federal government provides various benefits to married couples. In Massachusetts straight couples and gay couples receive the exact same marriage licenses. The argument goes like this: The federal government can't provide federal benefits to one group of married couples in Massachusetts while denying them to another group of married couples whose marriages are equally valid under the law. That doesn't mean there's a constitutional right to, for instance, tax perks, but if the federal government
chooses to provide those perks to some married couples, they have to provide them to all married couples.
Basic equal protection stuff. In states that already have gay marriage, those gay couples are just as married as straight couples, so the federal government doesn't have much of a case for discriminating against them.
That being said, the court is hearing the Prop 8 case on March 26 and then the DOMA case on March 27, so there's a good chance they'll try to untangle this thing all at once, in which case they probably will be addressing the question of a broad constitutional right to same-sex marriage.
