PARADISE VALLEY, Ariz. (AP) - Mitt Romney is ramping up his presidential campaign in a big way - just as Newt Gingrich emerges as a serious threat for the Republican nomination.
Over the next week, Romney's cross-country fundraising trips will cease, replaced by a more rapid-fire campaign schedule in early voting states. That means more TV ads, more media interviews and more hand-to-hand politicking in early-voting Iowa, New Hampshire, South Carolina, Florida and, Romney says, "a couple other states."
"We're just starting," the former Massachusetts governor said Tuesday before jetting off to court donors. "We're making our closing argument. ... You'll see me campaigning aggressively."
That would be a stark contrast to the cautious, calculated approach that Romney has taken all year as he focused on stockpiling campaign contributions for a drawn-out nomination fight.
The more intense focus is born out of timing - and necessity.
Voting for the GOP nomination begins in Iowa on Jan. 3 and Gingrich, a former House speaker and nationally known figure, has shot to the top of public opinion polls in Iowa and South Carolina while making gains elsewhere. Much to Romney's chagrin, Gingrich has benefited from the struggles of other rivals also considered more conservative than Romney, including Texas Gov. Rick Perry, Minnesota Rep. Michele Bachmann and Georgia businessman Herman Cain, who has dropped out of the race.
The primary has essentially become a two-way fight between Romney and Gingrich.
Romney's message will stay largely the same: He argues he has a business background that makes him the best candidate to create jobs and improve the economy - and the best candidate to beat President Barack Obama. Still, it's been fine-tuned in recent days, as Obama traveled to Kansas to invoke Teddy Roosevelt's pitch for a "square deal" for middle-class Americans.
"This election will be the choice between entitlement and merit, appeasement and resolve," Romney plans to say in speech Wednesday in Washington, echoing words he used in Arizona on Tuesday.
Behind the scenes, Romney aides are planning to start aggressively dipping into his mound of campaign cash to ramp up his presence on the TV airwaves.
He's already running ads in both Iowa and New Hampshire - positive spots that highlight his economic record - but he's not yet on the air with the heavy levels that usually come at this point in the campaign, as voters start paying attention.
He's also starting to increase his appearances on Fox News Channel, watched by many GOP primary voters, and has agreed to appear on "Fox News Sunday" on Dec. 18, his first appearance on a Sunday news show in more than a year and a half. Aides say it's a calculated effort that will help Romney across the map over the course of the nomination fight.
"I'll be on the air a good deal more than in the past," Romney said.
He's likely to get some help on that front in the coming weeks, when a super PAC aligned with Romney starts to engage by running ads, probably against Gingrich, in early voting states.
Aides refuse to say just how aggressively the campaign itself will go after Gingrich as the first caucus nears. The former House speaker is vulnerable to attacks on his record in Washington and his rocky personal life.
Romney offered hints of a more aggressive strategy toward Gingrich.
"We're going to make sure that the differences in our experience and perspective are well-aired. You can be sure I will not be quiet," Romney said during a Fox News interview Tuesday. "I am going to make sure my message is heard loud and clear. Gingrich is a friend, I respect him, but we have very different life experiences."
Romney campaign aides are counting on a long, drawn-out fight that will allow them to take advantage of their strengths compared with Gingrich's. Romney can afford to shift focus to retail politicking now because of how much money he's already sitting on - by the end of September, he had raised more than $32 million. Gingrich, by contrast, was still more than $1 million in debt and had raised just $2.9 million.
Romney has spent the past year building and maintaining organizations in states that don't hold early primaries. Under new rules for the Republican National Convention, candidates can collect delegates even from states where they don't win, as they will be awarded proportionally.
That means a longer fight - especially against Gingrich, who had to recover from his campaign's near-implosion in June - leaves Romney in a stronger position.
Romney's campaign is also relying increasingly on key campaign surrogates, particularly in Iowa. Gov. Chris Christie of New Jersey, who considered running for president himself, will campaign there for Romney on Wednesday. Romney's son Josh campaigned for him there recently as well. Romney's wife, Ann, met with activists in New Hampshire on Tuesday.
Romney will spend the rest of the week continuing his usual mix of fundraising and limited public appearances. He'll make a speech at the Republican Jewish Coalition in Washington on Wednesday and hold a fundraiser in Richmond, Va., on Thursday. On Friday, he has one campaign stop in Cedar Rapids, Iowa, ahead of Saturday's debate in Des Moines.