NASHVILLE, Tenn. — An American citizen held as an illegal immigrant in Davidson County — more than once — may have the strongest legal argument yet against the sheriff's role in a federal deportation program. Daniel Renteria-Villegas, a 19-year-old Portland, Ore.-born man, has been detained twice by the Davidson County Sheriff's Office on suspicion of being an illegal immigrant, in spite of having a valid Tennessee driver's license, passport, birth certificate and Social Security number. Now he's challenging the sheriff's very authority to participate in a federal immigration enforcement program called 287(g). He has filed a lawsuit demanding that Sheriff...