For sure, this is the one that worries me. Conflicts over issues like illegal immigration, 2d Amendment restrictions, abortions or drug laws could lead to states defying federal authority (or vice versa). This might involve National Guard deployments, sanctuary policies, or nullification-style resistance.
If a state creates laws against ICE agent masking, in clear violation of federal law, what happens? Does local law enforcement start trying to arrest federal officers? Does a governor attempt to mobilize the state National Guard against the feds? Sounds a lot like a Fort Sumpter moment.
KatNap Fever! 