Washington (CNN) - As Newt Gingrich continues his surge in the GOP primary race, Mitt Romney's campaign -rattled and concerned- clearly is moving into what one adviser calls "a fighting mode." Says another strategist close to the campaign: "Suffice it to say we know who we are running against, and we are ready."
From conversations with aides inside and close to the campaign, it's clear the Romney camp is in the process of devising a new attack strategy that goes beyond the former Massachusetts governor's declaration of Gingrich as a "career politician." The attack would take that label a step further and portray Gingrich as what one source describes as "an inside operator" who "has been selling access."
The contrast, these sources say, would be between Romney's experience– a Washington outsider, one-time Massachusetts governor, head of the 2002 Salt Lake City Olympics –and Gingrich's experience- as a former Houser speaker who "stayed inside the beltway" to peddle access.
"It's hard to figure out where to start with Gingrich," says one source. But they're not overlooking anything.
There's the personal life, for instance. Romney's camp sent out a flier in Iowa this past weekend reminding voters saying Romney is "the strongest Republican to beat Barack Obama and protect our values," adding that "Mitt Romney lives his values. He has been married to Ann for 42 years with five sons and daughters-in-law and 16 grandchildren…" The contrast, of course, is with Gingrich who is on his third marriage and had an extramarital affair -with his current wife, Callista- during the Clinton impeachment.
There are also issues the Romney camp believes are ripe for mining, such as immigration and global warming. In a recent CNN debate, Gingrich called for a more "humane" policy on immigration, which Romney has called amnesty. And Gingrich did an ad with Nancy Pelosi in 2008 supporting action to combat climate change. He now says the ad was a mistake and "really stupid." When Gingrich was asked Wednesday on Fox News if he thought global warming was man-made, he said "I believe we don't know."
It's more problematic, however, for the Romney camp to take on Gingrich on the matter of flip-flopping. They claim that Gingrich has changed positions on everything from his past criticism of Rep. Paul Ryan's budget plan to health care mandates. But they also know that Romney is vulnerable when it comes to the charge of flip-flopping.
There is also the hope among Romney aides -and some even predict- that Gingrich will self-destruct under the glare of the frontrunner scrutiny. "He's irascible, unelectable, confrontational," says one Romney partisan. "At some point, the real Newt will come out. Voters will start to question his temperament. At the end of the day, he's just unlikable."
The trouble for the Romney campaign is that the voters haven't exactly warmed up to its candidate. There is, as one GOP strategist close to the Romney campaign puts it, "a sliver of the GOP electorate that just wants the most confrontational candidate" to take on Obama, and that's why they like Gingrich. There are others, however, who are more interested in winning. "Electability will be key," this Romney partisan says.
At this point, though, Republican primary voters remain volatile. Gingrich now leads the polls in Iowa, South Carolina and Florida. Romney is still up in New Hampshire considerably, but Gingrich is gaining ground. And the real problem for Romney, according to one source, is that "we don't have a lot of time" before the Iowa caucuses, which are on January 3. So it's no surprise that Romney will begin to air TV ads in Iowa starting Friday. He has clearly decided to engage in the state, and there is little time to waste.
– CNN Senior Producer Kevin Bohn contributed to this story.