ROCHESTER, N.H. — Eleven minutes into his speech at a town meeting here, Mayor Giuliani started circling around the podium and addressing his 120-person audience without amplification. When an aide tried to hand him a microphone, Mr. Giuliani explained that his penchant for speechmaking while walking “comes from having been a trial lawyer.”

Mr. Giuliani’s experience as a former prosecutor serves him well in New Hampshire, where candidates must win over voters in person, much like members of a jury. Instead of criminals, his targets are Democrats he says are seeking to install in America “socialized medicine,” “Islamic terrorists,” and trial lawyers.

The Rochester town meeting capped off a two-day visit to the Granite State. While somewhat off the beaten path, Rochester has a population of about 30,000, which makes it worthy of political attention.

The visit by the former mayor of New York City could mark the beginning of a building momentum for his candidacy in New Hampshire. Until now, Mr. Giuliani has laid back somewhat from spending the kind of time and energy necessary to win over voters in a state used to lots of personal contact with candidates.

Last week, he began running radio advertisements here. He also distributed a flyer via direct mail outlining his ” twelve commitments to the American People,” which have become planks in his stump speech, and brandished a laminated card with the twelve commitments prior to a speech in Wolfeboro, N.H.

While Mitt Romney, a former governor of neighboring Massachusetts, has been leading in most polls, an American Research Group survey released yesterday put Mr. Giuliani one point ahead in New Hampshire, 27% to 26%. The same poll said support for Senator McCain had plummeted to 10% from 21%.

At the town meeting, Mr. Giuliani played a riff he has developed on the health care proposals of Democrats, likening their stances on health care to those of European or socialist states. “They are talking about socialized medicine … I have this feeling that Sarkozy is on an airplane headed to the United States, and Hillary, Barack, and John Edwards are on an airplane headed towards France,” Mr. Giuliani said, referring to the new president of France and the leading Democratic contenders, senators Clinton, Obama and Edwards.

Mr. Giuliani was also asked about the health care plan Mr. Romney had helped to create in Massachusetts. “Mitt doesn’t advocate universal health care for the entire country. I think he realizes Massachusetts has a very, very small number of uninsured,” he said. “It isn’t a good paradigm for the rest of the country. The rest of the country has significantly more complex problems,” added Mr. Giuliani, who also contrasted his management experience as a former mayor with the leading Democrats, all of whom are legislators, a tack Mr. Romney had taken during a visit to the state last week.

Although Mr. Giuliani’s campaign attempted to put the spotlight on his health care proposal during his New Hampshire visit, questions at his town meeting ran the gamut, as is usual in the state, from international and domestic issues to such odd-ball topics as medical marijuana.

Mr. Giuliani was particularly strong in dealing with a questioner who attempted to pin him down on the relationship between terrorism and “desperation.” “You’d like to think that, because that’s what your liberal education taught you to think. It’s not driven by desperation. It’s driven by religion out of control,” Mr. Giuliani said.

Mr. Giuliani also made points with his audience on the issue of immigration. His call to “end illegal immigration” was greeted warmly, but he received major applause when he said, “If you want to become a citizen, you’ve have to learn English, write English, and speak English.” Speaking in favor of legal immigration, he added: “We need to return to assimilation.”

In the battle fought by Messrs. Giuliani and Romney to win the support of New Hampshire Republicans who formerly backed Mr. McCain, the head of the Rochester’s Veterans of Foreign Wars post, Jim Golden, said he found Mr. Giuliani’s presentation “very impressive.”

Still, Mr. Golden said he was undecided between backing Mr. Giuliani or Mr. McCain, a Vietnam POW whom he said three-quarters of his fellow VFW still support. But Mr. Giuliani’s willingness to answer questions and respond to criticism won Mr. Golden’s praise. “He’s very forceful,” Mr Golden said. “He answered a lot of questions truthfully.”

There’s no question that Mr. Giuliani did well during his time in New Hampshire. Still unclear is the question of how much time he is willing to spend here. The campaign is ramping up its formal operations in the state, for example, by hiring a press secretary who will start work this week.

The Romney campaign remains nonchalant. “We’re focused on election day. We know polls go up and down,” a spokesman for Mr. Romney’s campaign in New Hampshire, Craig Stevens, said. “The more people see Mitt Romney, the more people like Mitt Romney.”

Mr. Giuliani’s supporters in the state are convinced of the same. Their success here will hinge on whether they can convince their candidate of that as well.