As Polls Open on Democratic Primaries, Reports on Two Bellwether Races Listen Download Embed Share Share this on Facebook (Opens in a new window) Share this on Twitter (Opens in a new window) Share this via Email U.S. Sen. Arlen Specter (D-PA) and his wife Joan attend a campaign event outside Citizens Bank Park May 17, 2010 in Philadelphia, Pennsylvania. ( William Thomas Cain / Getty ) Produced by Posey Gruener Produced by PRI and WNYC