President Barack Obama greets supporters during a campaign stop at the Alliant Energy Amphitheater, Wednesday, Aug. 15, 2012, in Dubuque, Iowa. The president is on a three-day campaign bus tour ... more 
President Barack Obama greets supporters during a campaign stop at the Alliant Energy Amphitheater, Wednesday, Aug. 15, 2012, in Dubuque, Iowa. The president is on a three-day campaign bus tour through the state. (AP Photo/Charlie Neibergall) less 
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Associated Press | Photo By Charlie Neibergall
Wed, Aug 15, 2012 5:44 PM EDT