Lloyd, its like believing that the "United" States military won't fire on American citizens if ordered.
These Border Patrol agents have families to feed, bills to pay, and careers to protect. They'll do as they're told, just like the military.
Our troopers here, even Sgt and above are being rotated back and forth to take their turn on the border. Its costing in stretched law enforcement in ALL COUNTIES, and billions moving them back and forth.