As independent Senator Bernie Sanders of Vermont announces his bid for the Democratic presidential nomination, we speak to former presidential candidate Ralph Nader. "We don’t want a coronation of Hillary Clinton," Nader says of Sanders’ run. We also talk about his new book, "Return to Sender: Unanswered Letters to the President, 2001-2015." The book is dedicated in part to the workers of the U.S. Postal Service.
