Barack Obama's a little bit country and a little bit rock 'n' roll. Or at least that's the message he delivered Thursday night by walking onstage at Invesco Field to U2's "City of Blinding Lights" (his usual entrance song) and exiting with Brooks & Dunn's "Only In America." Strangely enough, George W. Bush used that same flag-waving country hit during his 2004 re-election campaign.