Negative ads were so prevalent in the final week before the Florida primary that they accounted for 92 percent of all campaign commercials that ran.
And the most heavily broadcast commercial this past weekend was not one featuring Mitt Romney or Newt Gingrich but Tom Brokaw, the former NBC News anchor whose image the Romney campaign co-opted for an ad that used a 25-second clip from an old newscast on Mr. Gingrich’s political troubles.
These figures, compiled by the Kantar Media Campaign Media Analysis Group, attest to the bitter turn the race took after the South Carolina primary when Mitt Romney, Newt Gingrich and the “super PACs” working to elect them unleashed a barrage of attacks.
Mr. Gingrich, outspent and underfinanced, was the primary target.
The bulk of the ads were run by Mr. Romney and his PAC, Restore Our Future, which spent a combined $15.4 million on television and radio advertising in Florida. That compares with $3.7 million for Mr. Gingrich and his allies, according to an analysis by a Republican media strategist not working for either candidate.