President Barack Obama waves from the steps of Air Force One at Andrews Air Force Base in Md., Wednesday, Sept. 12, 2012. Obama is traveling to Las Vegas and Colorado to campaign (AP Photo/Susan Walsh)

Photo by: Susan Walsh

President Barack Obama waves from the steps of Air Force One at Andrews Air Force Base in Md., Wednesday, Sept. 12, 2012. Obama is traveling to Las Vegas and Colorado to campaign (AP Photo/Susan Walsh)