U.S. Rep. Tim Johnson (R-Urbana) will not run for re-election after serving in Congress for 12 years, and, two weeks after the Illinois primary, it is not clear whom Republicans will run in his place. Johnson represents Illinois' 15th Congressional district. But he planned to run in the 13th thanks to an Illinois remap that caused several Republicans to switch districts. Capitol Fax reports that Johnson may have decided to retire, because he thinks a GOP replacement candidate can still defeat "perennial" Democratic challenger David Gill.

Johnson is best known for calls to every constituent in his district and veering from GOP orthodoxy. He endorsed Ron Paul for president.