Nothing like jumping to conclusions

Really? You've already talked to "most of the Pennsylvanians who voted for Specter in 2004?" In 2004 he apparently collected about 20% of the democratic vote and has since seen 200k former Republicans in PA also switch to the Democratic party. Sounds to me like he's following his constituency.

"Most of the Pennsylvanians who voted for Specter in 2004 did so, in many cases reluctantly, on the good faith belief that he would vote with the Republican Party on leadership and at least nominally be part of the Republican coalition, even if departing from it on a number of key issue votes."