Behind the counter at the busy Hart Lane driver testing center here, Rosa King looked over the man's fistful of documents, including a Mexican birth certificate and a separate, typewritten English translation. The translation, Ms. King explained in Spanish, was not exact enough. It would have to be redone. When the man returned, he would be eligible for a card bearing his photograph, date of birth, height, eye color and the words "Not Valid for Identification." Tennessee is one of only two states that issue two different driver's permits: a license, for citizens and permanent residents; and a certificate for...