Arpaio can’t have it both ways - if he’s going to enforce federal statutes as a Sheriff, then he accepts federal jurisdiction. He knows this, and he knew this going in. I can’t figure out how he could reasonably plan on any different outcome for defying federal authority in this matter. Makes no sense.
Obama and Eric Holder don't like Joe because he enforces the law they won't. Makes them look bad. Doesn't exactly inspire confidence that the system is honest.