“Executive Orders only affect operations within the Executive Branch. They are not “laws” or even regulations.”
He could order the BATFE to do various absurd, illegal, things, and the jacked-booted thugs would comply.
They might, but without the assistance of local and state law enforcement they wouldn't have the manpower to make even scratch the surface (for instance, in my state of West Virginia the ATF has less than 50 agents for then entire state). All red state governors should do like they did with Obamacare and order state and local law enforcement not to assist.
If that's true, then we are headed for war.