BOSTON (AP) - Mitt Romney has a not-so-secret weapon against Newt Gingrich.
The former Massachusetts governor has built a mammoth political machine unrivaled in the GOP field, a campaign that's well entrenched in the four states to vote in January - Iowa, New Hampshire, South Carolina and Florida - and touches dozens of other states that his opponents have largely ignored.
At its national headquarters, Romney's team is executing a strategy that takes advantage of new party rules that award convention delegates in a different way. And supporters from Alabama to Alaska say they're prepared for an extended primary battle that could go well into the summer.
"This will probably take longer than a week or two to sort out," Romney said in Arizona this week. "My expectation is that it's going to be a campaign that is going to go on for a while."
In the meantime, Romney's team on Thursday began aggressively criticizing Gingrich's leadership and record. In a conference call arranged by Romney's campaign, former Missouri Sen. Jim Talent said Gingrich is "not a reliable and trusted conservative leader." Former New Hampshire Gov. John Sununu was more harsh, suggesting on the call that Gingrich's "irrational behavior," ''anti-principled actions" and "off-the-cuff thinking" could compromise his ability to be an effective commander in chief.
The Romney campaign's decision to go after Gingrich directly reflects a growing concern that Gingrich is a serious threat, despite Romney's public confidence in his long-term strategy.
New proportional voting rules give candidates a chance to claim partial victories in states that previously featured a winner-take-all system. Officials inside the Romney operation and the Republican National Committee argue that the new system encourages a long march to victory, similar to the Democratic battle between Barack Obama and Hillary Clinton in 2008.
It's a path that played well for Obama's nationwide network four years ago. And it's one that Romney hopes to emulate in the coming months, regardless of how things turn out in Iowa or New Hampshire.
"We're running for president of the United States, not president of the early states," Romney political director Rich Beeson said. "We're focused on the early states just like every other campaign, but we are also focused on the long term. We're looking at primaries in June."
Romney's campaign has already collected more than 1,300 endorsements from Republican activists and current and former elected officials from 44 states and Puerto Rico. Gingrich has collected fewer than two dozen endorsements in six states.
The organizational dominance offers Romney an army of high-profile supporters who are sharing political networks of their own. Romney has already has won support from eight U.S. senators, 45 House members and three governors. In many cases, the officials have been at it for months, raising money, spreading Romney's message and crafting state-specific strategies. They have been working in small towns and capitals alike in often-overlooked states like Vermont and Tennessee - even in Gingrich's home state of Georgia.
In some cases, people like Talent in Missouri have been working on Romney's behalf, officially or unofficially, for more than four years.
"He had a solid core of support going in," Talent said earlier. "Running for president is really running a campaign in a number of different states at once. Romney's organization started off very early in a number of states."
Beeson said the strategy makes Romney competitive regardless of which Republican rival emerges as his strongest competitor. In recent weeks it has become Gingrich. The former House speaker has so far won the endorsement of 14 elected officials in those states, according to a list provided by his campaign this week, while Romney has won the support of nearly 125 current and former GOP officials.
"Newt has no campaign," said Charlie Black, a longtime Republican strategist and lobbyist who worked for Sen. John McCain's presidential campaign four years ago. "No staff, no infrastructure, no fundraising mechanism."
Gingrich has hired aides in recent weeks in Iowa, New Hampshire and South Carolina. But Black argues that it's too late for him to assemble the type of operation needed to win primary after primary.
"You can't go all the way through this process without having a mechanism under you," he said.
Gingrich's organizational deficiencies have already begun to cause problems in places like Missouri, where he missed the deadline to appear on the ballot in the state's Feb. 7 primary. He insisted earlier in the week that he did not plan to compete in that contest because it does not award delegates. Missouri Republicans have set a separate caucus in March to confer delegates.
In Ohio, Gingrich supporters scrambled to scrape together thousands of signatures by Wednesday afternoon to qualify for the ballot there. The secretary of state's office said he met the requirement.
Gingrich faces similar tests in Virginia, Illinois and Indiana in the next several weeks. In every case, Romney's teams have already submitted the signatures or nearly accomplished the task.
But beyond simply qualifying for the ballot, Romney's organization gives him a running start in general election swing states like Missouri in a potential head-to-head matchup against Obama next fall.
"Barack Obama's going to be a very strong opponent - he almost won Missouri last time - and if the governor is fortunate enough to get the nomination, we're going to need a strong effort at every level here," said Talent.
Gingrich declared this week that he plans to challenge Obama in every state next year should he capture the nomination, and he began running his first TV ad. But there are few signs that he's organized supporters on the ground beyond the first three states on the Republican primary calendar.
In Virginia, Lt. Gov. Bill Boiling, a longtime Romney supporter, says the campaign is nearly finished collecting 10,000 signatures due by Dec. 22 to qualify for the ballot. And he's preparing for another fundraising event later in the week, which he expects will push Romney over the $1 million mark from Virginia supporters alone this year.
"At this point, Gov. Romney is well ahead of any other presidential candidate in Virginia in terms of having organization in place," Boiling said.
Virginia is one of 11 states tentatively scheduled to hold elections on March 6, which is known as Super Tuesday on the Republican primary calendar.
"I'd love to see Gov. Romney put this thing away by then - but I'm suspecting we'll still have a spirited race by the time Super Tuesday comes around," Boiling said. "Personally, I would not be surprised to see this race go into the summer. So a campaign has to gear up for that. If someone's strategy in this race is an early knockout punch, I think that's probably a bad strategy."