On a balmy Thursday morning in January, U.S. district court judge David Briones looked down at four small Mexican men in navy jumpsuits with “El Paso County Detention Facility” printed in faded white across their backs. Briones asked each how he pled. The replies in Spanish were repetitive and melodic: Culpable, culpable, culpable, culpable.

For Janet Bonner, the victory was routine. An assistant U.S. attorney who prosecutes immigration cases in this border city at the far western tip of Texas, Bonner wins dozens of cases each week. That’s because the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 both lengthened the list of offenses and toughened sentences — encouraging defendants to plead guilty to get reduced time.