The U.S. Constitution, Article VI provides that " ... all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding." On the other hand, the U.S. Supreme Court has ruled that customary international law is "part of our law, and must be ascertained and administered by the courts of justice of appropriate jurisdiction, as often as questions of right depending upon it are duly presented for their determination." Both treaties and international customs supersede all inconsistent state and local laws and also earlier inconsistent federal laws, but not the Constitution. This position is congenial to domestic enforcement of international human rights law. In reality, however, the legal position is marred by series of exceptions and deviations, which, in fact have become laws themselves to hide the actual legal position.
Alam, M. Shah
"Enforcement of International Human Rights by Domestic Courts in the United States,"
Annual Survey of International & Comparative Law: Vol. 10
, Article 3.
Available at: https://digitalcommons.law.ggu.edu/annlsurvey/vol10/iss1/3