FILE - In this Sept. 21, 2011 file photo, Sen. Claire McCaskill, D-Mo. listens on Capitol Hill in Washington. Republicans have long considered McCaskill one of their top targets in the

 

              FILE - In this Sept. 21, 2011 file photo, Sen. Claire McCaskill, D-Mo. listens on Capitol Hill in Washington. Republicans have long considered McCaskill one of their top targets in the
FILE - In this Sept. 21, 2011 file photo, Sen. Claire McCaskill, D-Mo. listens on Capitol Hill in Washington. Republicans have long considered McCaskill one of their top targets in the Senate in 2012. They just didn’t know who her opponent would be. GOP voters will decide among three contenders _ Sarah Palin-backed Sarah Steelman, businessman John Brunner, and Rep. Todd Akin, who was endorsed by former Arkansas Gov. Mike Huckabee _ in the marquee contest in Tuesday, Aug. 7, 2012, state primaries. No clear favorite has emerged in a primary race that will set up one of November’s most anticipated Senate contests. (AP Photo Manuel Balce Ceneta, File)