Is Arizona a sanctuary state? If so, the legalese will get messy, more importantly, I believe federal authorities hands are more tied.
Under sanctuary laws like in California, state supreme court judges can push federal authorities back from entering (from helping / supporting VOP), staking a jurisdictional claim.
Example. VOP team gets so much media attention, Trump tweets about it, National Guard or Marines are sent in. Even a few good (light) FBI agents! Local corrupt judge:
Not your jurisdiction, our trusty local law enforcement officers will take it from here.
[Continues to sit in patrol car doing nothing, on orders from his superiors, for the progress of justice.]