Pennsylvania state Rep. Jim Christiana (R), who Republicans had expected to run for a new, slightly Republican-leaning House seat in suburban Pittsburgh, won't run after all, he announced in a letter to supporters on Monday.

Christiana, seen by some Republicans as their best chance to win the seat, said he has "not finished some very important tasks" in the statehouse, including educational reform, and that he did not want to risk straining his relationship with his fiance ahead of their 2012 wedding.

Republicans hope they can take out the eventual winner of a Democratic primary between Reps. Jason Altmire and Mark Critz, who were forced into one district by redistricting. The new seat encompasses Altmire's suburban Pittsburgh territory as well as Johnstown, Critz's culturally conservative but economically liberal base.

With Christiana out, Keith Rothfus could be Republicans' best option. He narrowly lost to Altmire in 2010.