The Democrats are still looking for ways to boost their majority in the Senate, Talking Points Memo reports today. Gov. Ed Rendell told a regional TV network he’d tried to get Pennsylvania Sen. Arlen Specter to switch sides, and so had VP Joe Biden and Sen. Bob Casey. “He’s bound and determined to stay a Republican,” lamented Rendell, adding that, should Specter switch, he’d be unopposed for the Democratic Senate nomination. (More Ed Rendell stories.)