Chief correspondent

Every New Hampshire presidential primary is different from the others, and that is certainly the case this year. So far, it is the least-dramatic contested Republican primary in three decades. For Mitt Romney, that’s both a blessing and a possible curse.

The former Massachusetts governor flew out of the state Thursday for an overnight campaign trip to South Carolina, leaving the Granite State to rivals Rick Santorum, Newt Gingrich and Jon Huntsman Jr. (Ron Paul was away.) His departure was evidence more of his recognition that South Carolina looms as the biggest of the first three tests for his candidacy than of overconfidence about his standing in New Hampshire.

His campaign is continuing its due diligence four days before the balloting here Tuesday — making phone calls, knocking on doors and preparing to turn out its supporters. The team’s strategy is to follow the pattern that has worked so far.

Polls show Romney in a commanding position but also confronted with the high expectations that come with being a part-time resident and a former governor of neighboring Massachusetts. His advisers are mindful of what happened to Barack Obama here four years ago. He arrived as a heavy favorite after a big victory in Iowa. Five days later, Hillary Rodham Clinton defeated him in a stunning upset that he never saw coming.

Stuart Stevens, Romney’s chief strategist, said the Romney campaign reviewed Obama’s New Hampshire campaign and quickly came to the same conclusion that Obama and his advisers did after that loss: The candidate got swept away by his own reviews, by the crowds and by the polls, and he forgot to make the sale in a state where many voters don’t truly make their decisions until the final week.

Obama held big rallies that conveyed passion but masked how many voters were still up for grabs. He did not conduct real town hall meetings, which are the hallmark of New Hampshire presidential politics. He took people for granted. As Obama floated above the fray, Clinton got into the trenches, fielding questions and even meeting undecided voters on their doorsteps for part of a day.

Stevens said Romney will try to avoid Obama’s mistakes. By inference he means Romney will try to emulate the Clinton approach. That means he will stay humble and keep pushing until the final hours. Some large rallies will be held at the end, but his advisers are mindful that New Hampshire voters prefer smaller venues and the right to make contenders feel uncomfortable with their questions. Above all, the candidate will continue talking with voters.

The plan began to unfold Wednesday when Romney arrived after his eight-vote victory in Iowa for a town hall forum in Manchester, where he received the endorsement of Sen. John McCain (Ariz.). Some reviews of the event were terrible. Romney was confronted by hostile questions. Stevens shrugged off the critiques. Not the point, he said Wednesday night in Peterborough. The point was to show Romney taking on all comers, not avoiding their queries.

Right now, Romney is running against himself. He has been lucky in his opposition. No Republican front-runner in the past has managed to get this close to primary day in New Hampshire with so few direct attacks aimed at him. His opponents question his conservative convictions with increasingly pointed rhetoric, but haven’t put real money into television ads criticizing him.

A super PAC supporting Huntsman has spent a little less than $300,000 on anti-Romney ads, according to Kantar Media’s Campaign Media Analysis Group. Paul’s campaign has spent about $230,000 on ads going after the former governor. Overall, only a quarter of all limited ad money spent here has been focused on Romney.

Santorum is drawing strong and interested crowds for his town hall meetings, but he hasn’t made Romney the focus of his message. He is still introducing himself to voters here. For some time, Huntsman, who skipped Iowa and parked his campaign in New Hampshire, has been the most frequent critic of Romney but he doesn’t have much to show for it. Gingrich has ramped up his rhetoric — he called Romney a liar — but has lacked the desire, if not the resources, to run ads against Romney.

But there is another point to be made about the criticism. Romney was the target of several million dollars’ worth of disparaging ads here four years ago. As one of his advisers said Thursday, there isn’t a lot that his current rivals could throw at him that the New Hampshire electorate hasn’t already heard.

Romney is lucky also because of the split among conservatives. Santorum has the hot hand coming out of Iowa and he is looking to expand his support here. But in Gingrich he is facing another conservative who has the support of the New Hampshire Union Leader. The newspaper featured a front-page editorial by publisher Joseph W. McQuaid on Thursday urging voters to back Gingrich.

Romney will return late Friday to prepare for debates Saturday night and Sunday morning in which he is likely to be the target of all his opponents. He received the same treatment four years ago and didn’t handle it well. If the same pattern repeats, the dynamic could change over the weekend.

Part of the reason for the lack of drama is the Massachusetts factor. As a former governor of that state, Romney has a built-in advantage in New Hampshire. Democrats have experienced this in their primaries: Three times in the past six presidential races, Democratic politicians from Massachusetts have won the primaries here. (A fourth candidate, Edward M. Kennedy, lost to President Jimmy Carter in 1980.)

That home-court advantage creates a potential problem for Romney, whose only real foe right now is expectations. Because victory is expected, he will receive less credit for winning here than anywhere else. But a weaker-than-expected showing will add to the questions about whether he can win the GOP nomination. That’s why, despite the absence of drama here, there can be no cruise control for Romney in the final days.