After getting drubbed by Newt Gingrich in South Carolina, Mitt Romney is redoubling his attempt to bury him in negative advertising. The Romney super PAC Restore Our Future bought another $5 million in airtime yesterday, bringing the campaign's total investment in Florida to $13 million, a state whose size makes ads more important than previous primary states. The most recent buy includes the first negative ads run directly against Gingrich by Romney’s camp. Gingrich, fueled by another $5 million from casino magnate Sheldon Adelson, is trying to fight back, making a $145,000 buy with Fox News. In the latest sign of Romney's newly aggressive tone, he attacked Gingrich as an “influence peddler” at last night’s debate.