Overview: With the 2012 campaign season moving from primary to election mode, Bill invites back to his studio master media decoder Kathleen Hall Jamieson for a closer look at the role misinformation will play in the Obama vs. Romney TV ad slugfest. Jamieson, who runs the Annenberg Public Policy Center of the University of Pennsylvania, including the sites FactCheck.org and FlackCheck.org, discusses the sharp increase in deceptive advertising in the 2012 race, and equally-alarming new obstacles to campaign ad transparency. Later in the show, Bill talks to RoseAnn DeMoro, who heads the largest registered nurses union in the country, and will lead a Chicago march protesting economic inequality on May 18. DeMoro is championing the Robin Hood Tax, a small government levy the financial sector would pay on commercial transactions like stocks and bonds.