What would be the effect of the United States ratifying a treaty that is incompatible with its constitution?
Does a treaty have to be compatible with the US constitution to be implemented?
A treaty that is incompatible with the U.S. Constitution is void to the extent it is unconstitutional. See, e.g., Doe v. Braden, 57 U.S. (16 How.) 635, 657 (1853) ("The treaty is . . . a law made by the proper authority, and the courts of justice have no right to annul or disregard any of its provisions, unless they violate the Constitution of the United States."); The Cherokee Tobacco, 78 U.S. (11 Wall.) 616, 620 (1870) ("It need hardly be said that a treaty cannot change the Constitution or be held valid if it be in violation of that instrument."); De Geofroy v. Riggs, 133 U.S. 258, 267 (1890) ("It would not be contended that [the treaty power] extends so far as to authorize what the constitution forbids."); Asakura v. City of Seattle, 265 U.S. 332, 341 (1924) ("The treaty-making power of the United States . . . does not extend ‘so far as to authorize what the Constitution forbids.’") (quoting De Geofroy, 133 U.S. at 267); Reid v. Covert, 354 U.S. 1, 16 (1957) ("This Court has regularly and uniformly recognized the supremacy of the Constitution over a treaty.").