While many advocates concede that a federal court battle has a slim chance of success, they point to the successful nullification of the Real ID Act as a blueprint to resist various federal laws that they see as outside the scope of the Constitution.
Some say that each successful state-level resistance to federal programs will only embolden others to try the same – resulting in an eventual shift of power from the federal government to the States and the People themselves.
I’m not sure comparison can be made to the Real ID Act. The Real ID Act was impractical to implement (as well as being useless), had to be done by the states, and the states among other things said we aren’t doing it unless you give us a LOT more money. Defying Federal firearms laws requires a win in the courts or use of force against Federal law enforcement. Neither of which I see as very likely.
I agree with the goal, I’m just not convinced it will work unless there were a large number of states that went along with it. In which case a Constitutional Amendment would be feasible.