“He’s still a Massachusetts guy. That’s pretty much the way I feel about it,” said Dr. Modugno, 68, who said he and his wife now intend to vote for Mr. Santorum. “I was only thinking about Romney because we want to beat Obama. That’s our key. Now we want to get the most conservative person we can get in order to do that job.”

Three days before the New Hampshire primary, the Romney campaign is calling — and recalling — its supporters to make sure they are still on board. Mr. Romney’s organization is more robust than any other candidate’s. And he is seen here as something of a favorite son, particularly along the well-populated southern tier of the state that borders Massachusetts.

For his part, Mr. Romney is trying to make the case that he is the Republican candidate who can go the distance. When he arrived here Friday evening, he was traveling with Gov. Nikki Haley of South Carolina, who delivered a testimonial on his behalf.

“When he leaves here,” Ms. Haley said, “I want him to come to South Carolina with the biggest momentum possible.”

The presence of the South Carolina governor underscored how Mr. Romney is looking beyond New Hampshire, which has been known to agitate voters here who have grown accustomed to personal attention from candidates.

“I just didn’t like that yesterday he went to South Carolina and forgot about us,” said Konstantin Dolzhamskiy, 21, who works for the Diplomatic Observer Program in Manchester. “I’m a little mad at him, but over all it was O.K.”