@inthehands I don't believe that's true, though I admit I'm not sure what the margin is. States may not interfere with federal agents doing their jobs, within the law. But local cops could stop and arrest an ICE agent for drunk driving, for example, even if they're on duty. That's not interfering with the performance of their duty, because drunk driving is not part of their remit, and it's a public safety issue requiring immediate responce.