Question: do treaties have to comply with the constitution

Answer: Yes, Additionally, an international accord that is inconsistent with the U.S. Constitution is void under domestic U.S. law, the same as any other federal law in conflict with the Constitution. This principle was most clearly established in the case of Reid v. Covert. The Supreme Court could rule an Article II treaty provision to be unconstitutional and void under domestic law, although it has not yet done so.