The U.S. Republican White House hopefuls faced New Hampshire voters Tuesday in a first-in-the-nation primary which is all but certain to strengthen frontrunner Mitt Romney's hold on the nomination.
Analysts were eager to see how well the former Massachusetts governor and millionaire venture capitalist does compared to polls that have consistently given him a big lead in the bellwether state and to see who comes in second.
Romney hopes a romp -- after a narrow win in the Iowa caucuses last week -- will propel him into South Carolina's January 21 primary -- the first in the South, where his more conservative rivals sense their best shot at a victory.
By tradition, the first ballots in New Hampshire were cast shortly after midnight in two tiny towns with a combined turnout of 32 voters.
In Dixville Notch (population 75) Romney tied former US China envoy Jon Huntsman with two votes each out of nine cast. In Hart's Location (population 42) Romney was the most favored Republican with five votes.
Voting began at several statewide locations at 6:00 am (1100 GMT).
New Hampshire officials expect around 325,000 voters to head to the polls, most of them Republicans because Democratic President Barack Obama is running unopposed for his party's nomination ahead of the November 6 elections.
The GOP primary is closed to Democrats but open to the state's undeclared voters, its term for registered independents who are notoriously unpredictable.
The candidates themselves were expected to make made-for-television public appearances -- telephoning undecided voters, exhorting volunteers to get supporters to the polls -- before settling in to await the verdict.
Former House speaker Newt Gingrich was first to go on the attack against Romney on Tuesday, saying voters faced a clear choice between "a Reagan conservative who cuts taxes and a Massachusetts moderate who raises them."
"What you don't want to do is nominate somebody and find out in September that they have a fatal weakness and then you can't do anything about it," Gingrich said in a CNN interview.
"All of us should be tested in January, February, March, to make sure that whoever gets the nomination is tough enough to stand up to Obama."
Gingrich, a one-time frontrunner, has been trailing in opinion polls after a blitz on his own record by Romney allies.
A daily tracking poll released Monday by Suffolk University in nearby Boston found Romney with 33 percent of likely voters, followed by Representative Ron Paul at 20 percent.
Huntsman was at 13 percent, Gingrich at 11 percent, and Christian conservative and former senator Rick Santorum at 10 percent, following his extremely close second-place finish in last week's Iowa vote.
Texas Governor Rick Perry and former Louisiana governor Buddy Roemer trailed in low single digits.
A vast campaign war chest and high-profile endorsements have fed Romney's image as the man to beat, but he faces stubborn doubts about his conservative credentials and has been unable to push his nationwide Republican support above 30 percent.
In South Carolina, Romney faces pushback from conservatives who think he is a flip-flopper and from evangelical Christians wary of his Mormon faith.
Romney has faced a blistering attack of a different sort in the days before the New Hampshire primary, as Gingrich, Perry and Huntsman assail his record over jobs lost at companies bought by his venture capital firm, Bain.
Gingrich led the charge against his rival over his time at Bain, which dismantled some of the firms it bought while reaping vast profits.
"They apparently looted the companies, left people totally unemployed, and walked off with millions of dollars," he told NBC television.
"Look, I'm for capitalism. But if somebody comes in, takes all the money out of your company, and then leaves you bankrupt while they go off with millions, that's not traditional capitalism."
Romney struck back, telling the Nashua Chamber of Commerce "I have been in business. I have learned some things fail and some things succeed, that's how it works ... those that succeed make our overall nation stronger."
Romney's foes have also seized on a comment he made as he argued that Americans ought to be able to switch health insurance companies -- "I like being able to fire people" -- to argue that Romney would target US workers.
"The insurance company will have an incentive to keep you healthy. It also means that if you don't like what they do, you can fire them. I like being able to fire people that provide services to me," he said in Nashua.
Huntsman charged that Romney "enjoys firing people, I enjoy creating jobs," and added: "It may be that he's slightly out of touch with the economic reality playing out in America right now."