Adolfo Cardenas smiles faintly at the memory of traveling with his 14-year-old son from Honduras to the U.S.-Mexico border in only nine days, riding buses and paying a smuggler $6,000 to ensure passage through highway checkpoints. Father and son walked about 10 minutes in Arizona's stifling June heat before surrendering to border agents. Instead of being released with paperwork to appear in immigration court in Dallas, where Cardenas hopes to live with a cousin, they were bused more than an hour to wait in the Mexican border city of Mexicali.