Isn't it way more complicated than that? A state can obviously make things illegal in that state that aren't illegal nationally, they do it all the time. There would have to be a positively conflicting law to be a debate. (like with drug laws) Normally going in the other direction. Pretty sure you'd need a constitutional amendment to bind a state from doing something. Like in the case of drugs where federal law is often more strict, there's a whole body of case law around that. They made a commerce clause argument, and there's a doctrine they can't force the states to act to enforce a federal law, but also the states can't countermand the federal law, there's a whole history of courts dealing with the interactions.