Just over a year ago, Arlen Specter was campaigning for the Presidential ticket of John McCain and Sarah Palin as a Republican Senator of Pennsylvania. Of course, when Arlen Specter voted for the Democratic backed stimulus package this past spring, the vote emboldened conservative challenger Pat Toomey to the point where it drove Specter out of his former Republican Party and into the Democratic Party citing poor GOP primary poll numbers.

Initially, Specter came into the Democratic Party as the only viable challenger for the nomination. At that point, he was a conservative Democrat vowing to go against the Employee Free Choice Act and a public option in health care . As his primary challenger Joe Sestak pointed out in a recent Huffington Post op-ed, where he tries to paint Specter as “Pennsylvania’s Joe Lieberman,” Specter has switched his position on both of these issues among others. Furthermore, Specter has also positioned himself to the left of Joe Sestak on the Afghanistan escalation painting himself as a dove while Sestak has taken a hawkish position.

A recent Quinniapiac poll has Specter tied with Toomey in a general election match up, while in May he had a 53-33 lead over Toomey. Specter still has a comfortable lead over Joe Sestak in the primary with a 53-30 lead, in fact, he has made gains since October when the numbers were 44-25 for Specter.

So for now, at least in his primary race, Specter’s leftward leans have worked to his favor. However, if Rep. Sestak can get his voice heard and push his message that Specter has only made his leftward leans to advance his long time career of opportunism, it could be damaging to Specter in a primary race. So far, obviously, it has not resonated. One thing is for certain, Pennsylvania politics could be changing. One year ago, no one would imagine Toomey, a Santorum-style conservative, tying or beating a Democrat in statewide polls.