Americans love talk shows. In a typical week, more than 13 million Americans listen to Rush Limbaugh, whose syndicated radio show is carried by about 600 stations. On television, Oprah Winfrey's syndicated talk show is seen by an estimated 30 million viewers each week. Talk show hosts like Winfrey and Limbaugh have become iconic figures, frequently quoted and capable of inspiring intense opinions. What they say on the air is discussed around the...