Pennsylvania’s stagnant population growth led to the Republican-controlled legislature drawing two Democrats out of existence. In Southwestern Pennsylvania’s 12th District, two Democratic incumbents were drawn together. Rep. Jason Altmire was given a substantially larger portion of the new district he fought for with Rep. Mark Critz, but Critz was able to win his home base by such an overwhelming margin that he overcame this geographic disadvantage. Strong geographic splits were also evident in the 17th District, where Rep. Tim Holden, a Blue Dog Democrat previously in a marginal seat, was given a Trojan horse of a blessing: a new district full of Democrats who were chomping at the bit to primary him from the left.
