Iowa City, Iowa (CNN) - Newt Gingrich is getting a nasty taste of what’s to come.
As the former House speaker stood in a classroom at the University of Iowa and began to detail his vision for a federal brain-science project dedicated to curing Parkinson’s and Alzheimer’s diseases, Occupy Iowa City protesters started shouting.
The rowdy disruption lasted for several minutes. One Republican in the room ripped a written speech from the hands of one demonstrator.
But Gingrich eventually seized control of the event as the protesters were led out of the room.
That wasn’t the worst of it. At the end of a question and answer session following Gingrich’s remarks, one man in the crowd attacked the GOP front-runner’s personal life.
“Seems like you have a Ph.D. in cheating on your wife,” the unidentified man said.
It was a bitter end to a day that began with a barrage of attacks from Mitt Romney and his supporters, who are out to blunt Gingrich’s momentum heading into the final weeks before the Iowa caucuses.
The Romney offensive sought to enflame tensions at the top of the Republican field little more than a day after Gingrich issued a plea to his fellow contenders to wage a positive campaign.
But Gingrich would have none of it.
“They should run their campaign the way they want to and I'm going to run my campaign the way I want to,” Gingrich told reporters at a news conference after the University of Iowa event.
Gingrich conceded he was drawn into a war of words with Romney earlier in the week. This time, he said he was not going to take the bait.
“My campaign is going to be focused on positive ideas and positive solutions and I'm frankly taking the gamble that the American people care about solving our country's problems - not just watch politicians beat each other up,” Gingrich added.
Earlier in the day, Romney seemed to question the former speaker’s seriousness as a presidential candidate in an interview with the New York Times.
“Zany is not what we need in a president. It may work on talk radio… But in terms of a president, we need a leader,” Romney told the Times.
The pro-Romney political action committee Restore Our Future was also on the attack. It aired a new negative ad that portrays a Gingrich candidacy as a dream-come-true for Democrats.
“Barack Obama’s plan is working. Destroy Mitt Romney. Run against Newt Gingrich,” the ad states.
Adding to the video onslaught, the Romney campaign released a new web ad that features Gingrich and House Democratic Leader Nancy Pelosi in their now infamous plea to combat climate change.
When pressed by reporters to respond to Romney’s attacks, even Gingrich's spokesman declined.
“We’re going to stay positive in this campaign,” R.C. Hammond said.
Gingrich, who has ridiculed Occupy Wall Street protesters in the past, offered an olive branch to the protesters who interrupted his speech.
“I’d be glad to talk to them about how to create jobs,” Gingrich said.
It was clearly a different Gingrich on display. The former speaker exhibited restraint, holding back his trademark acid-tongued comebacks.
But the Gingrich confidence could not be contained.
Asked about recent polls that show he poses less of a challenge to President Obama than Romney, Gingrich made a less-than-modest comparison.
“I’m at about where Reagan was with Carter at this stage,” Gingrich said.
Gingrich told reporters he’s looking forward to taking a new bus across Iowa in the next two weeks to make his case to caucus-goers face to face.
As he walked out of the news conference, he told reporters he is still having fun.