The National Republican Congressional Committee added six GOP recruits to its list of those "on the radar," the second tier of four in its Young Guns recruitment program.

The candidates: law student Ricky Gill, who is challenging Rep. Jerry McNerney (D-Calif.); Army veteran Tom Cotton, who is running for retiring Rep. Mike Ross's (D-Ark.) seat; former Rep. Matt Salmon (R-Ariz.); Arizona state House Speaker Kirk Adams; former city Commissioner of Winter Park, Fla., Karen Diebel; and attorney Keith Rothfus in western Pennsylvania.

Salmon and Adams could face each other in a primary depending on how Arizona's nonpartisan redistricting commission draws its maps, while it is unclear where Diebel will run until Florida finishes its redistricting process. Similarly, Rothfus is likely to run in a newly drawn district outside of Pittsburgh, but he could face either Rep. Jason Altmire (D-Pa.) or Rep. Mark Critz (D-Pa.), depending on how redistricting works out there.

Republicans had such a strong year in 2010 that there are very few House districts left for them to target. Most of their new pickup opportunities will be created by redistricting, which is greatly altering the congressional lines in many states.