Arlen Specter's sudden polling struggles in his Democratic primary race with Rep. Joe Sestak are particularly glaring when you look back at the pre-election polls from his last primary challenge.
Back in 2004, the last time Specter sought re-election, he was opposed in the Republican primary by then-Rep. Pat Toomey. Specter barely survived that fight, posting a 51-49 percent victory -- a margin of just 17,000 votes. What is notable is that Specter never trailed Toomey in a single poll before that primary. In the final three independent surveys conducted before the April 27, 2004 contest, Specter posted leads of six, six and five points. Those numbers weren't that comforting for the incumbent, since he was just under 50 percent in each survey, but they at least suggested a decent chance of victory for him.
Things look different for Specter now. With the May 18 primary now just eight days away, Sestak has erased Specter's once-sizable advantage and pushed into the lead. A Muhlenberg College/Morning Call poll out today has the challenger ahead by four points, while Rasmussen has Sestak up by five. Both of these polls have Specter significantly farther below the 50 percent mark than he was at this point in his '04 race.