Legislation by Assemblyman Gil Cedillo, D-Los Angeles, would change police procedures at drunken-driving checkpoints, prohibiting officers from arresting drivers and immediately impounding their cars if their only offense is not having a license. Supporters say the bill, AB353, would keep DUI checkpoints from being turned into traps for otherwise law-abiding illegal immigrants who cannot obtain licenses. "In most parts of California, you basically have to have a car," said Mark Silverman, director of immigration policy at the Immigrant Legal Resource Center. "You have to be able to drive to survive, to get anywhere. Because of that, the truth is, immigrant...