Yesterday the U.S. Supreme Court heard arguments in the case of Upper Skagit Indian Tribe v. Lundgren, concerning the limits of tribal immunity. Two years ago, during the period when Republicans were keeping the ninth seat on the Court vacant, the Justices deadlocked 4-to-4 on an analogous matter, leaving in place a 5th circuit decision favorable to tribal sovereignty in what seemed to some a borderline case. The opinion was per curiam, and all that issued was a brief announcement, "the judgment is affirmed by an equally divided court." At any rate, the particular borderline at issue this week is a different one. It involves the in rem jurisdiction of state courts and whether that sort of jurisdiction works to limit the immunity of tribes. For those who don't know the lawyer's Latin, in rem means "about the thing." The "thing" in question is often though not always a parcel of land. In this case, the Lundgren family and the tribe are e...