Ted Robbins, NPR's Southwest correspondent based in Tucson, filed this report for Thursday's Morning Edition.

The Senate immigration bill calls for tripling a controversial federal court program called Operation Streamline. It now handles 70 cases a day in Tucson's federal courts and would be expanded to handle 210 cases, with a $50 million appropriation.

The program takes people caught crossing the border illegally, gives them prison sentences, then deports them. It's hugely expensive — but does it work?