"The U.S. Constitution trumps any provision of any U.S. Treaty. Period end of story, so politicians can insert any language they want into a Treaty, but at the end of the day any provision in conflict with our constitution loses. Missouri v. Holland, 252 U.S. 416 (1920)("[a] Treaty cannot be valid if it infringes upon the Constitution"). In other words the President is forbidden from executing in a Treaty what Congress is barred from doing." This explanation comes from a video found at Prison Planet. So, to answer the question of which trumps what--does a UN Treaty trump the US Constitution? I don't know.