The Supreme Court has appointed Prof. Vicki Jackson of Harvard Law School to be "amicus curiae" in United States v. Windsor to brief and argue in support of the point of view that the Court does not have jurisdiction to decide the merits of the case. Presumably, the Court fears that because the Solicitor General (representing the government), BLAG (representing the Republican leadership of the House of Representatives), and Edie Windsor, the plaintiff-respondent, all want the Court to rule on the merits, none of these parties has an incentive to make a strong argument against appellate jurisdiction in this case. The Court likes to have opposing points of view represented in the argument, thus the appointment of Prof. Jackson.
On one level, this it not shocking or unprecedented. The Court from time to time makes such appointments when its review of the papers filed in a cert petition makes clear that the parties will not present adverse arguments on a point that strikes the Court as important. This reaffirms, of course, that the Court's addition of these jurisdictional questions signals the Court's view that they are important questions that need to be argued and answered.
That said, I find it difficult to believe that the Court would find that the government does not have an important stake in the case. This is not an abstract dispute in which the government is seeking an advisory opinion from the Court. This is a real controversy about whether the government must continue to enforce Section 3 of DOMA, which it doesn't want to do but feels bound to do until the statute's unconstitutionality is judicially determined (or Congress repeals it). The government agrees with the district court and the 2nd Circuit that DOMA is unconstitutional, but it is not offering to settle the case by refunding Edie Windsor's estate tax payments, because, as the Attorney General has said, he and the president concluded that they are obligated to continue enforcing Section 3.
Several hundreds of thousands of dollars in taxes are at issue here; this is a tangible case, not just a symbolic one. Edie Windsor certainly had standing to file for a tax refund, based on her lawful marriage conducted in Canada in 2007 and the fact that by the time her wife died in 2009, there was appellate authority and executive authority in New York that same-sex marriages conducted out-of-state would be recognized by the state. As the 2nd Circuit (and 1st Circuit) have noted, there are important federalism concerns in this case, about how DOMA interferes with the state's ability to confer marital rights on same-sex couples. There is no doubt that the determination of who can marry has been considered a matter of state law under our federal system. So there are important legal issues with practical everyday consequences, a real plaintiff who has suffered those consequences, a government agency (the IRS) that is embroiled in litigation because DOMA requires it not to recognize lawful state marriages between same-sex couples, and an outstanding judgment against the government that is the subject of this appeal.
That's my 2 cents!