US President Barack Obama shakes hands with soldiers before speaking at Buckley Air Force Base in Aurora, Colorado, on January 26, 2012 on US energy and the steps the Administration is taking to promote energy security. Obama denied Republican claims he was waging class warfare as he set out to sell his call for tax hikes on the rich in states crucial to his reelection bid. AFP Photo/Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)