WASHINGTON (AFP) - Republican White House hopeful Mitt Romney unleashed a hard-hitting campaign ad Monday blasting Obama's handling of the economy, the top issue on voters' minds in the 2012 race. Romney himself does not appear in the video, which turns Obama's June 3 comment that "there are always going to be bumps on the road to recovery" into an attack highlighting historically high unemployment of about 9.1 percent. Instead, the ad shows people lying in a road, then standing up each in turn to declare "I'm an American, not a bump in the road" and holding up a placard with their name followed by "stands with Mitt."