Yesterday the ACLU of Louisiana enrolled in a lawsuit filed by Johnny Duncan, aka "Johnny UnBlackWorthy," a veteran and resident of Amite who was detained by police because they objected to a sign on his car reading "You Might be a Nigger!." Mr. Duncan, himself an African-American, is the author of a book of political and social commentary entitled "You Might be a Nigger!," and the sign on his car was to advertise the book. Mr. Duncan was detained outside of an Amite restaurant, where the police told him that the sign on his car was "obscene." When he refused...