Arizona State Senator Russell Pearce is a leader in the movement for the states to do more of the immigration enforcement, since the federal government has shown little enthusiasm for the heavy lifting. He reports that Arizona is improving after instituting its state laws (modeled on federal statutes): jobs are up and crime is down. The prison population is declining for the first time..
Furthermore, he notes, ”States have inherent authority to enforce the laws; they’ve never been pre-empted. They can enforce federal law. We arrest bank robbers every day on federal law. Nobody protests that.”