Joe Raedle/Getty Images

ABC News' Michael Falcone reports:

TAMPA, Fla. - As Florida voters cast their ballots on Tuesday, Mitt Romney spoke of the lessons he learned from the race he lost to Newt Gingrich in South Carolina just 10 days ago.

"In South Carolina we were vastly outspent with negative ads attacking me and we stood back and spoke about President Obama and suffered the consequence of that," Romney told reporters outside his campaign headquarters here, adding: "If you're attacked, I'm not going to just sit back, I'm going to fight back and fight back hard."

As it turns out it was Romney who vastly outspent his opponents.

According to sources tracking media buys during the South Carolina primary, Romney and his allies, which include two super PACs, purchased more than $4.6 million of television airtime during the run-up to the state's Jan. 21 primary. The two pro-Romney super PACs, Restore Our Future and Citizens for a Working America, chipped in millions.

By comparison, the Gingrich campaign and a pro-Gingrich super PAC, Winning Our Future, spent more than of $2.2 million in the state.

The Romney campaign alone spent more than double the Gingrich campaign on TV advertising. Romney did not begin running negative television ads against Gingrich until after his South Carolina loss, but the super PAC supporting him, was spending the vast majority of its money on negative attacks.

Romney is also swamping Gingrich on the Florida airwaves. According to media buying sources, Romney and the Restore our Future super PAC has spent four-and-a-half times more than Gingrich and the Winning our Future super PAC - a difference of more than $12 million.

Many of those ads have forcefully attacked Newt Gingrich, including one that uses news file footage from 1997 when Gingrich was convicted of ethics violations in the House of Representatives.

"It would be wonderful if campaigns were nothing but positive," Romney said on Tuesday, "but that's certainly not the reality."