DAVENPORT, Iowa -- Newt Gingrich accused his Republican primary opponents of "reprehensible behavior" for running TV ads attacking him and his record, and said he will launch a 44-city bus tour to barnstorm Iowa before the Jan. 3 caucuses.
Gingrich appeared at a private security firm in Iowa on Monday afternoon in his first appearance in the state since last Thursday's debate. Since that debate, he has been criticized for not campaigning in the state. And for over a week, he has been under assault from rival campaigns, super PACS supporting his opponents and anonymous shadow groups in Iowa criticizing all aspects of his record and personal life.
Gingrich did not wait one second in his remarks before launching into an attack on his primary rivals, whom he did not mention by name.
"What this campaign should be about in the next 15 days ... is who has the best ideas, who has the best solutions," Gingrich said.
"It's candidly very disappointing to see some of my friends who are running who have so much negative junk."
Gingrich, the former House Speaker from Georgia, said he will "be coming back again and again" to Iowa, where he has seen a large lead evaporate over the past week. A Public Policy Polling survey out Monday morning showed him having lost his lead and now in third place behind Paul and Romney.
The bus tour will begin on Dec. 27 or Dec. 28, a Gingrich spokesman told The Huffington Post, depending on whether the Newsmax debate scheduled for the 27th takes place or not.
Gingrich said his opponents should "have the courage to have a campaign that would match ideas, and didn't see whose consultant could be the nastier, or whose consultant could run the more clever destructive ad."
"The only person who profits from Republican ads attacking other Republicans is Barack Obama and I think that's pretty reprehensible behavior from the point of some of the candidates," Gingrich said.
The only campaigns which have technically criticized Gingrich, in TV ads, are those of Rep. Ron Paul (R-Texas) and Texas Gov. Rick Perry.
But the biggest ad buy has been from a super PAC supporting former Massachusetts Gov. Mitt Romney, which has poured $3.1 million in TV ads into Iowa for a spot knocking Gingrich for having lots of "baggage," and arguing that President Obama will have an easy time of defeating Gingrich in the general election.
The Romney campaign has sent a mailer criticizing Gingrich to Iowa households.
After Gingrich's speech to about 50 or so voters from Iowa and some from across the Mississippi River in Illinois, he admitted that he had allowed the barrage of attacks against him to go on unanswered for too long.
"You get enough negative ads before you start answering them, your numbers go down for a while," Gingrich said.
But he said that he believes his attempt not to criticize his opponents by name, or unless he is first attacked, "will turn out to be a huge asset."
"It reflects badly on other Republicans if they haven't got anything positive to say for themselves and they've got to rely on consultants trying to tear down a fellow Republican, so they're in effect doing Barack Obama's work. I think the average Republican is going to be very unhappy," Gingrich said.
Gingrich did, however, take one shot at Paul for comments in Thursday's debate that were critical of Republicans who want to use military force, or reserve the right to do so, to stop Iran from obtaining a nuclear weapon.
"I will stand apart from some of our candidates in believing that we need a strong defense," Gingrich said.
The Romney campaign declined to comment and the Perry campaign did not respond to a request for comment. But the Paul campaign and the Romney super PAC, Restore Our Future, both blasted right back at Gingrich.
"What Newt Gingrich should find reprehensible is his own record. All of Newt's baggage can only hide behind his flawed big ideas for so long. We are simply putting a spotlight on him and his record," said Brittany Gross, a spokeswoman for Restore Our Future.
Jesse Benton, Paul's campaign manager, was in no mood to tolerate sermonizing from Gingrich.
"Let's be clear here. Newt Gingrich supported TARP, bailouts, individual healthcare mandates and [a] litany of other big government schemes. He was even paid millions to advocate for Freddie Mac, one of the arch-culprits of the Housing Crisis!" Benton wrote in an e-mail to The Huffington Post. "The only thing that is reprehensible is his record, and the fact that [he] is trying to campaign as a conservative when he is really a big government liberal."
This article has been updated to reflect the results of Monday's Public Policy Polling survey and comments from the entirety of Gingrich's speech, the Paul campaign and Restore our Future.