U.S. Sen. Herb Kohl (D-Wis.) is photographed in Racine, Wis., on Oct. 14, 2005. Kohl said Friday, May 13, 2011, he's not running for a fifth term in 2012, a blow to Democrats who now will have to ... more 
U.S. Sen. Herb Kohl (D-Wis.) is photographed in Racine, Wis., on Oct. 14, 2005. Kohl said Friday, May 13, 2011, he's not running for a fifth term in 2012, a blow to Democrats who now will have to defend another open seat against Republicans in a swing state. Kohl is the fifth Democratic senator to announce his retirement ahead of the 2012 election. less 
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Associated Press | Photo By Journal Times, Mark Hertzberg
Fri, May 13, 2011 2:37 PM EDT