Brad Pierce thinks the federal government has gotten too big, a cause that's driving the one-time President Obama voter to opt for a Republican in the 2016 presidential race. But the "middle-of-the-road" retiree from Rye, N.H., also names global warming as a top concern and wants more done to promote renewable energy.

More than any one issue, however, Pierce - who used to work in computer sales and as a remodeling contractor - wants a president who can solve problems. To him, Gov. Christie is that candidate.

"He's had tremendous experience," said Pierce, 71, who attended a recent town-hall meeting in Stratham, N.H., where Christie wooed a receptive crowd with a focus on national security - telling sobering stories about the aftermath of Sept. 11 - and cast himself as the most "tested" and trained candidate.

In New Hampshire, where the New Jersey governor has focused his efforts, the share of likely GOP voters naming Christie their top choice has ranged from 4 percent to 8 percent in recent polls.

Identifying those voters - and others who might be inclined to join them - helps campaigns chart a path to victory.

"If you don't have a solid idea of the demographics of a voter who supports you, it becomes increasingly difficult to target those voters and get them out on Election Day," said Mike Dennehy, a Republican strategist in New Hampshire and adviser to Arizona Sen. John McCain's presidential campaigns.

But for Christie - and other candidates with single-digit support in the congested Republican field - pollsters say there isn't enough information to identify specific demographic trends. In a recent Suffolk University/Boston Globe poll of 500 New Hampshire GOP primary voters, for instance, Christie had 4 percent support - or 21 people in the poll.

Some conclusions, however, can be drawn, including that moderate voters are responding more to Christie than conservatives, said David Paleologos, director of the Suffolk University Political Research Center. Christie had 8 percent support among the moderates in the poll, compared with 4 percent of all GOP voters.

"That's probably the best description of his base: moderates," Paleologos said.

Similarly, Ohio Gov. John Kasich's support, which was 9 percent overall in the poll, climbed to 16 percent among moderates. Florida Sen. Marco Rubio and former Florida Gov. Jeb Bush also did better among moderates. "Those are the people [Christie] has to pry support away from," Paleologos said.

Christie - whose favorability has risen in recent polls - isn't just competing for moderates. A source close to his campaign said the governor also was positioned to draw support from conservatives, particularly secular voters focused on national security. And with his outspoken style, Christie's appeal extends to voters who support Donald Trump, the source said.

In recent interviews in New Hampshire, several voters named Trump and Christie among their favorites in the race.

"I would pick Trump because of his business knowledge and Christie for all of the other things," said Nancy White, 73, an independent voter from Manchester, N.H., as she awaited Christie's arrival for a town-hall meeting at the Park Place Lanes bowling alley in Windham, N.H.

John Consigli, 63, of Chester, N.H., also endorsed a Trump-Christie ticket. "We're shocked" that Christie hasn't been doing better in polls, Consigli said, since he's "very outspoken." (Consigli would give Trump top billing: "It's the difference between a business guy and a politician.")

More voters who were considering Christie, however, named other candidates with political experience as the competition for their support.

Several tables down from the Trump-Christie backers at the Windham bowling alley was Judy Mulligan, a school employee from Merrimack, N.H. She likes Christie and Bush, who are "just intelligent people who have done a lot for their own states."

"I am not going to go the Trump route - just not doing that," Mulligan said. She voiced concern about Trump's "very brash way of talking to people. I can't see him dealing with heads of state very well."

While Christie has emphasized his national security message following the Paris attacks, a number of voters inclined toward Christie also named fiscal issues as priorities.

"Everybody in the race and across the country should be concerned about the debt," said Ed Marceau, 59, of Stratham, who favors Rubio, Christie, and Bush. Retired from a civil service job with the Navy, Marceau also said defense was a top issue.

Bill Stearns, 73, of Bedford, N.H. - who is volunteering for Christie's campaign - said Christie was "the most likely to get things done," based on the candidate's experience dealing with Democrats. If he had to pick a second choice, Stearns said, it would be another governor: Kasich.

While Christie has been lambasting Democrat Hillary Rodham Clinton on the campaign trail, her strength as a candidate could help him and other Republicans competing for moderates in the New Hampshire primary, said Paleologos, the Suffolk pollster. If Clinton's success on the Democratic side seems guaranteed, more undeclared voters - who make up about 40 percent of New Hampshire's registered voters - may participate in the GOP primary, Paleologos said.

Most undeclared voters, however, typically vote either Republican or Democratic, rather than acting as "free agents," said Andy Smith, director of the University of New Hampshire Survey Center.

"It's more a factor of showing up than it is they switch from electorate to electorate," Smith said. "We like the myth of a lot of freethinking New Hampshire voters, but it's just not the case."

Not that there aren't voters who defy conventional wisdom. A few, for instance, said they liked Christie and Texas Sen. Ted Cruz. While Christie says he has governed with "conservative values," he also emphasizes compromise; Cruz is known as more of a Republican hard-liner.

Gary Laviolette, 47, of Jaffrey, said Christie and Cruz both respected the Constitution and believed in "a strong America."

"I believe in closing our borders. I believe in taking care of our own," said Laviolette, a paper-mill worker who liked that Christie doesn't "smooth-talk us." He also likes Rubio and retired neurosurgeon Ben Carson. "I don't trust Trump as far as I can throw him," Laviolette said, describing Trump as having "too much favor" with liberals.

New Hampshire voters often make up their minds "last minute," and the final decision tends toward electability more than ideology, Smith said.

In the primary, "it doesn't necessarily make sense about what candidates they go to," Smith said. "In the minds of a lot of these voters, who are not hard-core partisans, there's not much difference between these candidates."