Last year, in Sanchez-Llamas v. Oregon, the U.S. Supreme Court held that a suspect's failure to raise his rights under the Vienna Convention on Consular Relations in a timely fashion under state law barred him from later arguing, in a habeas corpus petition, that the arresting officers' failure to inform him of his Convention rights rendered his conviction invalid. Although the ruling rested in part on the Court's conclusion that a Vienna Convention violation does not give rise to an exclusionary remedy, in the course of upholding the procedural bar, the Court rejected the argument that it was bound to accept as authoritative the interpretion given the Convention by the International Court of Justice in prior cases involving the United States. The ICJ had held that a state procedural bar would be ineffective under such circumstances. In rejecting the notion that the ICJ interpretation is binding, the Supreme Court (per CJ Roberts) appeared to invoke a principle of constitutional avoidance. Under Marbury v. Madison, the Court noted, the (U.S.) judiciary says what the law is, and that includes treaty law. Accordingly, the Court refused to construe the Vienna Convention as requiring binding deference to the ICJ. After giving the ICJ's ruling "respectful consideration," CJ Roberts concluded that his interpretation was superior.
Sanchez-LLamas thus left open the question of what would happen if a treaty required the Supreme Court to accept as binding the interpretation of that treaty by an international court such as the ICJ, even as its invocation of Marbury suggested that the Court would treat a requirement for such binding effect as unconstitutional.
Meanwhile, human rights lawyers have increasingly turned to international human rights tribunals for relief where the U.S. courts have failed them. Consider, for example, a case currently before the Inter-American Commission on Human Rights. Jessica Gonzales sued individual officers and the police department after they failed to enforce a protection order, resulting in her estranged husband's murdering their three children. Gonzales sued but her case was ultimately dismissed by the U.S. Supreme Court. She then filed her petition before the IACHR, which will hold a hearing on the case on March 2. Ms. Gonzales is represented by my former student (now a supervising attorney in the Columbia Human Rights clinic) Carrie Bettinger-Lopez and her students, as well as various public interest organizations. They have compiled the key documents here and here. Even if the petition succeeds, it will not directly "reverse" the Supreme Court, so that the Marbury power will undoubtedly remain intact. But in the long run, as cases of this sort proliferate, the United States Supreme Court will come under increasing pressure to find ways to give effect to the judgments of "higher" courts. Perhaps it will do so as a matter of comity, retaining the formal power to make its own independent decisions, or perhaps, more radically, it will accept a subordinate status, at least with respect to the meaning of international law.