Pizzapinochle said:
...Federal law sets the "floor" and "ceiling" for state law. Between the floor and ceiling, states have discretion....
I'm sorry, but that is a gross oversimplification, and consequently a misstatement, of the area of federal preemption and choice of law (where the laws of multiple jurisdictions could be applicable). This is a huge and complex subject, and one really won't get anywhere if he starts his journey from that point.
For example, there is first the question of whether the Congress had the constitutional power to enact it. Then there can be the question of what the limits of the application of that federal might be within the confines of the scope of Congress' constitutional power. That for example was the sort of question addressed in
Wickard v. Filburn, 317 U.S. 111 (1942) and
Gonzales v. Raich, 545 U.S. 1 (2005), where the federal laws were clearly within Congress' power under the Commerce Clause; but the constitutionality of the application of those laws to particular activities was in question.
Also, if the particular issue addressed by the state law is also addressed by the federal law, there's the question of whether the particular federal law was intended to "occupy the field", i. e., be the final word on the subject. In that case the federal law preempts the state law and applies instead of the state law.
On the other hand, if a court decides that the federal law did not reflect an intent to occupy the field, in order to decide if federal law or state law applies a court will need to decide if the state law is consistent a federal policy concern or would, on the other hand, frustrate the federal policy furthered by the law.
Sometimes federal law will be explicit about how a conflict between federal law and state law is to be resolved. An example which comes immediately to mind involves the confidentiality of medical information regulation under HIPAA. Those regulations expressly provide that they don't supersede state laws to the extent providing great protection of an individual's confidentiality interests.
On the other hand a federal law could be found to preempt state law if either expressly or by inference the federal law was intended to promote national uniformity with regard to a particular issue.
So if you want federal law to preempt state laws, you will first need to be able to draft the law in such a way that it can be enacted by Congress within the scope of Congress' constitutional powers. Second, you will want the law to expressly state that it is intended to occupy the field and regulate the subject on a uniform basis nationally.
And of course whether any such law is good for us or good for our opposition will depend on our respective political strengths.