Arlen Specter called his opponent in the Democratic Party primary, Joe Sestak, a “flagrant hypocrite” and accused him of registering as a Democrat “just in time to run for Congress.”
Remember that Specter just switched from Republican to Democrat, because polls showed that he was going to lose the Republican primary. Sestak says that he registered as an independent while he was in the military because he believes that officers should be non-partisan.