The most hotly-debated issue with respect to the Supreme Court's announcement that it will hear two major gay-rights cases is whether it will decide the cases at all. In addition to the crucial substantive issues relating to the constitutional status of sexual orientation, the Court has asked the parties in both the DOMA and Prop. 8 cases to brief questions of "standing." Because the source of the Court's power of judicial review is their authority under Article III to resolve "cases and controversies," parties have to demonstrate that they have a direct stake in the case for the courts to have jurisdiction. In both the the DOMA and Prop. 8 cases, the executive branch—either the White House or the California governor's office—whose law has been held unconstitutional by lower courts has refused to defend it, so there's an argument that nobody has an interest in appealing the decisions. There are two questions about standing and these cases: 1) should the Court find standing, and 2) will it?
On the normative question, I'm inclined to think the Court should interpret standing loosely and hear serious constitutional arguments if at all possible. And while I think it's entirely appropriate for Obama and California Governor Jerry Brown to not defend these laws, a clear signal of their disapproval, it would be a problematic precedent if this was interpreted as denying anyone the opportunity to defend the government's law in court. (What if lower courts had ruled the PPACA unconstitutional while a Republican was in the White House? Would there be no recourse if a federal appellate court held it unconstitutional?) Walter Dellinger, however, argues, at least in the Prop 8 case, not granting standing would be justified:
In this case, the issues of standing and the merits are in deep resonance with one other. Linking them is the fact that no one is injured when a gay couple is married. That is why the state has no rational reason to deny a license to gay and lesbian couples in the first place... But in the world in which we live, a straight couple's right to marry remains unimpaired by gay marriage. This case could be over—indeed it should be over—because no one has a legal interest in denying someone else's happiness.
This reasoning is superficially appealing, not least because it would lead to the result (marriage equality in California) that I would prefer. But it's hard to escape the conclusion that this reasoning is effectively the same kind allowing conservatives on the court to deny standing to litigants whose claims they don't like. To assume that nobody has an interest in defending the California law is begging the question. The Court should require marriage equality in California—but they should do so honestly, by ruling on the merits.
Leaving aside what the Court should do, what will they do? My guess is that, because the lower court rulings both resulted in the anti-LBGT law in question being struck down, the votes to deny standing won't be there. With the possible exception of Chief Justice Roberts, the conservative justices who are most sympathetic to narrow standing rules are vanishingly unlikely to join any opinion that results in same-sex marriage being legalized in California. The more liberal justices who would like the result of denying standing have no reason to prefer that to ruling on the merits unless there's no other way of getting a fifth vote. That might be the case if there was no way of striking down Prop. 8 without granting a national right to same-sex marriage, but upholding the 9th circuit opinion is another option. The ninth circuit ruled that you can't take away same-sex marriage rights once you have granted them, leaving some leeway for swing vote Justice Kennedy to approve of a narrow ruling that would strike Prop. 8, but leave the road to national same-sex marriage rights long and winding.
Obviously, if there was no chance that the Court would deny standing, they wouldn't have bothered to ask the question in the first place. But my guess is that they will claim jurisdiction in both cases, and that's the right thing to do.