- 8th District, U.S. Rep. Joe Walsh (R-McHenry) vs. Tammy Duckworth. Walsh is an outspoken Tea Partier who squeaked to victory in 2010 vs. Rep. Melissa Bean, who barely campaigned. Duckworth ran for Congress in 2006 and lost.
- 10th District, U.S. Rep. Robert Dold (R-Kenilworth) vs. Democrat Brad Schneider. When Mark Kirk won re-election in 2008, he was the only Republican in the House whose district voted for Barack Obama and John Kerry. The new map makes the district more Democratic.
- 11th District, U.S. Rep. Judy Biggert (R-Hinsdale) vs. ex-Rep. Bill Foster (D-Naperville). Biggert was first elected in 1998, but the new district is more Democratic. Foster won a special election in 2008 and was re-elected that year, but lost in 2010.
- 17th District, U.S. Rep. Bobby Schilling (R-Colona) vs. Cheri Bustos, an East Moline council member. Re-districting made the district more Democratic, taking in part of Rockford.
13th District, Republican Rodney Davis vs. Democrat David Gill. Davis is a congressional staffer who was given the nomination when U.S. Rep. Tim Johnson (R-Urbana) withdrew from the race. Gill has run before and lost.
12th District, Republican Jason Plummer vs. Democrat William Enyart. Plummer won the Republican primary for lieutenant governor in 2010. Enyart was handed the nomination to replace the winner of the Democratic primary, who withdrew. U.S. Rep. Jerry Costello (D-Belleville) is retiring, so this would be a Republican pickup if Plummer wins.
Other districts in the state are considered safe for the incumbent party.
Brian Gaines, a political science professor at the University of Illinois, says the incumbent Republicans who are targeted should not be written off. “The first rule of congressional elections is that incumbents do very well. Even when they’ve been there only one term, they have a way of getting their name out,” he said. “But one term, with a very deeply changed district, it’s a lot harder.”