NOGALES, AZ - DECEMBER 10: Hundreds of people wait to pass from Mexico into the United States at the border crossing on December 10, 2010 at Nogales, Arizona. Despite Arizona's tough immigration enforcement laws, thousands of Mexican citizens have permits to work in the U.S. and commute daily from their homes across the border in Mexico. Border crossings, known as "ports of entry," are run by the U.S. Office of Field Operations, which is part of the department of U.S. Customs and Border Protection. Port personnel are the face at the border for most visitors and cargo entering the United States and are authorized to stop, question, search and examine everyone entering the country. (Photo by John Moore/Getty Images)
