The federal Supreme Court frequently nullifies state laws as they did with portions of the AZ anti-illegal law, but no where does the constittuion give them that authority. The Supremacy Clause of the Constitution says in Article 6 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. That says federal laws are supreme ONLY if made in pursuance of the constitution. So any state has the right so declare a federal law in violation of the constitution and void. Remember the states came first and they created the federal govt merely to act as their agent in selected matters such as fighting a war. In no way did they want the federal govt put above the states.