Perhaps you misunderstood my original post. Of course the Supreme Court was free to give effect to the Avena judgment if it had, in fact, believed that the Avena judgment was an accurate determination of U.S. obligations under the Vienna Convention. But the Supreme Court already determined several years ago in Sanchez-Llamas that Avena was wrongly decided, that the ICJ erred when it concluded that Vienna Convention violations were not subject to waiver under state procedural default rules. That decision established that the Supreme Court would not defer voluntarily to Avena’s legal conclusions. So the issue in Medellin was whether, despite the ICJ’s legal error, the Avena judgment constituted a “binding” obligation on the state and federal courts of the United States. The Court ruled yesterday that Avena was not binding because Congress had determined ICJ rulings are not binding — when the Senate ratified the Optional Protocol, Article 94 of the UN Charter, and the ICJ Statute, and when Congress failed to adopt subsequent implementing legislation. The Court made clear that the issue of whether ICJ judgments constitute binding federal law is to be determined solely by Congress; it explicitly rejected the notion that courts are empowered to “pick and choose which [treaty obligations] shall be binding United States law . . . and which shall not.” Slip Op. at 19.

Regarding Justice Stevens: I gather you believe that the Texas Court of Criminal Appeals erred when it determined that Texas law barred Medellin from seeking further collateral review of his Vienna Convention claims. But I doubt that Justice Stevens believes that it is his place to second-guess a Texas court’s interpretation of Texas law. He is free to suggest that the Texas legislature should change Texas law; I was questioning his apparent suggestion that the Texas courts should consider Medellin’s claims anew despite the statutory bar.