and who gets to decide what federal laws are constitutional? but playing your game, where do those words get used in the Constitution "constitutional federal laws"?????
"This Constitution, and the Laws of the United States which shall be made in
Pursuance thereof; and 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."
So only those federal laws which are in pursuance of the Constitution, or constitutional, are supreme over the states. When a law is not constitutional, or in pursuance of the Constitution, the states can nullify that law as per the 10th Amendment, since the Constitution does not forbid nullification.