How much power does the president really have? Is obstruction of justice an impeachable defense? Can you indict a sitting a president? These are just a few of the questions Corey Brettschneider, professor of political science at Brown University, sets out to answer in his new book, The Oath And The Office: A Guide For Future Presidents. In honor of Constitution Day, Monday September 17, Brettschneider joins Soledad O’Brien to talk about his new book on presidential policy and power.