The immigration check points returning from Rocky Point seem to be legal. They are within 100 miles of the border with a nexus to a border crossing spot, and the stop consists of only a couple of questions. The only issue, per case law would be if they used drug sniffing dogs as probable cause for a search of the vehicle. The ruling also came from a New Hampshire court, so I would question any application to Arizona. If a federal court were to make a similar ruling, it may apply.