IANAL, but I'm not sure that's how laws in nested jurisdictions like the US work. If a city doesn't want to spend resources to enforce state law, or if a state doesn't want to spend resources to enforce a federal law, who's gonna make 'em? Obviously constitutional restrictions exist for all US governments, but you can't like, coerce a sub-jurisdiction to do anything beyond that, can you? That's why ten states rejected the ACA and were able to legally do so.