In this article, Professor Weisburd explores the implications of Medellín v. Texas for the President’s authority to affect domestic law through reliance on his authority to conduct the foreign affairs of the United States. He argues that the Court was correct to reject arguments that, on the facts of the case, the President could look to a delegation of authority from Congress or from the Senate as treaty-maker, or that President could treat the matter as resting on his power to settle claims against foreign governments, or that the President’s obligation to “take care that the laws be faithfully executed” would provide the necessary grounding for his action. He also argues that there are reasons to support the Court’s result stronger than those that appear in its opinions, and that critics’ arguments are not very convincing. Finally, he suggests some implications of the result in Medellín.