Philip Elmer-DeWitt; Christopher R. Browning; Political Comedy; Mairead Maguire

Philip Elmer-DeWitt, associate editor at Time Magazine, reveals how different countries are vying for negotiating power before the upcoming global Earth Summit in Rio de Janeiro. Historian Christopher R. Browning shares his book, "Ordinary Men," which follows the progress of a single German battalion tasked with executing Jews in Poland during WWII. Political comedians Richard Belzer, Will Durst, and Randy Credico weigh in on the presidential candidates and controversial political issues. Nobel laureate Mairead Maguire talks about her grassroots movement, Community of the Peace People, which aims to bring about change through nonviolence in Northern Ireland.