Rep. Jason Altmire (D-Pa.), long expected to be a Republican target in 2012, has his first GOP challenger: state Rep. Jim Christiana has announced an exploratory committee to run for Congress.

Christiana, a two-term state legislator, is from Beaver County, outside of Pittsburgh and in Altmire's current district. While it's unclear what the state's congressional lines will be and Christiana does not mention Altmire by name in his exploratory announcement, many expect the Republicans in the state to target Altmire, making his district more Republican.

The Democrat won his Republican-leaning seat in 2006 and since then voted against cap-and-trade legislation and Democrats' health insurance reform law. Those breaks with the party helped him to hold on to his seat in the 2010 Republican wave with a 51-49 percent win.

But Republicans in the statehouse are likely to break apart his district and make it a bit more GOP-friendly, which could make his reelection bid just as tough as last year's.