Newt Gingrich hits Ron Paul even as he vows to stay positive

MASON CITY, Iowa - Newt Gingrich, buffeted by intense criticism from GOP rivals and sagging poll numbers, pledged Wednesday to keep his campaign positive in the closing days before the Iowa caucus. But he also reiterated his discomfort with Rep. Ron Paul serving as commander-in-chief.

Appearing at Mason City's Southbridge Mall, Gingrich told a crowd of about 250 people that a "super PAC" that supports him will begin airing ads on his behalf over the next six days "and they're going to be positive."

"I think that we have enough trouble in this country that we ought to have a campaign about positive ideas and positive solutions, because the only person helped by negative ads in Barack Obama and our business is to defeat him, not to help him," he said.

Asked by reporters about his comments on CNN on Tuesday that he would have trouble supporting Paul even if the Texas congressman was the hypothetical Republican nominee, Gingrich said his comments were in direct response to a question and not intended as an attack. He said Paul's general opposition to the use of military force is troubling.

"I'm very uncomfortable with the idea that a commander-in-chief would think that it was irrelevant to have an Iranian nuclear weapon because I regard an Iranian nuclear weapon as very dangerous," he said.

The former House speaker also said that his rival Rick Perry "did the right thing" in announcing a legal challenge to being excluded from Virginia's upcoming primary election ballot for failing to meet the signature requirement. Gingrich's campaign also failed to get enough signatures.

"We haven't looked at that [legal challenge], but I think it's interesting for everybody who thought it was my problem that you also have Governor Perry also pointing out that Virginia is a very difficult ballot to get on," he said.