Romney Launches Pennsylvania Ad Attack on Santorum

April 10 (Bloomberg) -- Bloomberg's Peter Cook reports that Mitt Romney’s presidential campaign has an attack ad set to air in Pennsylvania targeting Rick Santorum. The $2.9 million ad buy is a spot focusing on Santorum’s “historically embarrassing” loss in his 2006 bid for a third U.S. Senate term in Pennsylvania. He speaks on Bloomberg Television's "In The Loop." (Source: Bloomberg)