I want to know the answer to the following question:
What happens when both the federal and state governments have regulations that overlap?
All the background I'm provided with is that "In some areas, like aviation and railroads, the federal government has developed a comprehensive scheme that preempts virtually all state law, while in others, like family law, a relatively small number of federal statutes (generally covering interstate and international situations) interacts with a much larger body of state law.". Is that enough to answer the question?