In Presidential elections, not really. It was very close in 2004, but otherwise it always seems to skew safely Democratic, except in Republican landslides like 1980-1988. If you compare PA to Ohio, for example, it has consistently been a little more Democratic in each election than OH. Republicans like to think it's a battleground, but it has two big urban Democrat strong-holds what with Pittsburg and Philly and too many blue-collar Dems in the rural areas. 2004 was a close call for the Dems because economics were on the back-burner while war/terrorism and Kerry's murky vietnam/swiftboats background was the main headline. Ohio is the state that becomes a lot more open to both parties.
Obama won PA by only 3 points more than the nationwide margin. That means that, if Reagan had won with a 3-points margin in PV, he would have carried PA. That makes it definitely a swing State.
