Think of the words "Illegal alien" or "welfare queen." What color faces do you see in your mind? Now think about about phrases like "real Americans," or  "hard-working taxpayers." What color faces do you see now? Ian Haney López argues such phrases are "dog whistles," coded language used by politicians to get certain messages across. López is a professor at the University of California, Berkeley and is the author of Dog Whistle Politics: How Coded Racial Appeals Have Reinvented Racism and Wrecked the Middle Class.