In response to Justice Stephen Breyer's 2015 Brennan Center Jorde Symposium Lecture, 104 Calif. L. Rev. 1553 (2016).

This Essay describes and defends the Supreme Court's role as a filter between international law and the American constitutional system. In this role, the Court ensures that when international law passes into the U.S. legal system, it does so in a manner consistent with domestic constitutional values. This filtering role is appropriate, the Essay explains, in light of the different processes used to generate international law and domestic law and the different functions served by these bodies of law. The Essay provides examples of this filtering role in four scenarios: the intersection of treaties and individual rights; the relationship between the treaty power and American federalism; delegations of authority to international institutions; and the domestic application of customary international law.