With Air Force One in the background, President Obama speaks to supporters during a campaign event on the apron at Austin Straubel International Airport in Green Bay, Wis., on Thursday, Nov. 1, 2012. Mr. Obama resumed his presidential campaign with travel to the key battleground states of Wisconsin, Colorado, Nevada and Ohio today. (AP Photo/Pablo Martinez Monsivais)

Photo by: Pablo Martinez Monsivais

With Air Force One in the background, President Obama speaks to supporters during a campaign event on the apron at Austin Straubel International Airport in Green Bay, Wis., on Thursday, Nov. 1, 2012. Mr. Obama resumed his presidential campaign with travel to the key battleground states of Wisconsin, Colorado, Nevada and Ohio today. (AP Photo/Pablo Martinez Monsivais)