POMPANO BEACH, Fla. - Mitt Romney said tonight in an interview with ABC News that he thinks Newt Gingrich is "flailing about" as he begins to recognize he's "in trouble" in Florida.

"I feel good about Florida and feel good about the sendoff," Romney said during an interview aboard his campaign bus. "And as I watch Speaker Gingrich flailing about and casting about and attacking, I have to think that he's seeing a diminution of support and recognizing he's in trouble here."

"And it's not because of something we've done, or Rick Santorum's done, I think it's because people look at Speaker Gingrich and recognize this is a guy who was paid over a million dollars to stand up for Freddie Mac," Romney said. "People here are angry about Freddie Mac and angry about what Freddie Mac did to the value of their homes."

Gingrich launched a new set of attacks against Romney today, suggesting that the "Republican Party will not nominate a pro-abortion, pro-gun control, pro-tax increase moderate from Massachusetts."

Romney called Gingrich's attacks "unbecoming" and "painfully revealing."

"Speaker Gingrich's comments over the past few days have been sad and painfully revealing," he said. "I think we are seeing a side of Newt Gingrich that we haven't seen since he was speaker several years ago, and I think we understand why it was his members felt that they didn't want to support him. You have hundreds of people who worked with Newt Gingrich when he was speaker and only a handful who are willing to support him now.

"I think unfortunately we're seeing the qualities that got him into so much trouble when he was speaker of House," he added. " I hope he'll return to the issue. These personal character attacks are really unbecoming of a presidential candidate."

Asked whether he is concerned that the GOP race has turned too negative, a suggestion made even by one of his own surrogates, Sen. John McCain, Romney said the character issues lobbed by Gingrich have "surprised" him.

"I think what's surprised me in the last couple of days is seeing Speaker Gingrich bring out character attacks," he said. "It's one thing to talk about differences on issues and go back and forth on our respective views, but for the speaker to launch an assault on another person's character is really unbecoming, and I think sad and painfully revealing of his own shortcomings."

One of his own campaign ads, released Saturday, came under fire when NBC News asked for it to be removed due to the usage of a "Nightly News" clip that they argued was out of bounds. The ad, titled "History Lesson," simply plays a newscast from the night Gingrich was ordered to pay fines for his ethics violations.

Romney would not say explicitly tonight that he would like to see the ad taken off the air.

"We'll review with our attorneys and those at NBC what's the right course for that ad," Romney told ABC News. "The advantage of an ad like that is that speaker Gingrich can't complain that somehow that our campaign is distorting what happened.

"This is a news report spoken by a person of extraordinary credibility and describes quite accurately the challenge that occurred when Newt Gingrich was speaker," Romney said. "He was a failed leader of our party at a time when we needed him very badly to be highly effective. People looked to him to carry the torch and he let them down."