Newt Gingrich

Newt Gingrich addresses a meeting of the Rotary Club during a campaign stop at the Dubuque Golf and Country Club. (Scott Olson / Getty Images / December 27, 2011)

Newt Gingrich, trying to reverse a slide in Iowa by positioning himself as the unabashedly positive alternative to his trash-talking rivals for the GOP presidential nomination, unleashed an unexpectedly harsh attack today against his chief rivals, former Massachusetts Gov. Mitt Romney and Rep. Ron Paul.

Gingrich has been the target of an avalanche of negative advertising, including TV spots, robocalls and brochures. He has often said in the last few days that he would take the high road. But his anger surfaced Tuesday when he was asked by CNN's Wolf Blitzer what he would like to say to Romney about the attacks.

"All I'd say is, 'Mitt, if you want to run a negative campaign and you want to attack people, at least be man enough to own it.' "

He said Romney was a "moderate Massachusetts governor, who is in fact very timid" with proposals for the economy.

Paul's record, said Gingrich, is one of "systemic avoidance of reality."

Referring to reports about newsletters sent out under Paul's name containing racist and anti-Semitic rants, Gingrich said that the Texas congressman had "a long way to go to explain himself."

Gingrich said he would not vote for Paul for president. When asked whom he would vote for if it came down to a choice between Paul and President Obama, he answered only that Paul could never be the Republican nominee.

Voters, said Gingrich, "will not accept somebody who thinks it's irrelevant if Iran gets a nuclear weapon."

"As a protest, he's a reasonable candidate," said Gingrich. "I don't see how you can engage Ron Paul as the nominee."

Just before Gingrich was interviewed by CNN, he was the keynote speaker at a weekly luncheon of the Rotary Club in Dubuque. A Rotarian asked Gingrich to draw a distinction between himself and Romney, who had mildly tweaked the former House speaker earlier in the day for failing to qualify for the Virginia primary ballot.

In a Facebook post, Gingrich's campaign manager had compared the setback to that suffered by the United States when Pearl Harbor was bombed in 1941. "Obviously, the Virginia setting was not the best hour of his campaign," Romney said in New Hampshire.

At the prompting of a Rotarian, Gingrich recalled President Reagan's admonition against Republicans attacking fellow Republicans.

"I believe in Reagan's 11th commandment," said Gingrich. "I don't want to be invidious about Gov. Romney, who is a very competent manager and a smart man."

But in a conversation with reporters after his speech, foreshadowing his CNN interview, Gingrich was less diplomatic, calling Romney  "a Massachusetts moderate [who] raised taxes, created a larger government, imposed greater costs on business... and I think the difference in our records is clear. It's also clear in our policy."

He will try to counteract the extraordinary barrage of attack ads, Gingrich said, by talking to Iowans, making himself available to rebut the attacks in telephone "town halls" and appearances across the state.

But, a reporter noted, there is only a week left.

"We have lots of time, in the age of instant television," Gingrich said. "I trust in the people of Iowa to look at something that's clearly baloney and know that it's baloney."

He issued a challenge to Romney, who, sensing opportunity to fare well in Iowa as Gingrich has slipped in the polls here, left New Hampshire and headed to Iowa today.

"Is he willing to stand up on the same stage--just the two of us--and let's talk about the differences in our policies and our approaches?" Gingrich said.