For all the partisan energy in New Hampshire this week for a pair of presidential debates, the voters who could determine the outcome of the first-in-the-nation primaries don't call themselves Democrats or Republicans.
They're the famously unpredictable New Hampshire independents -- technically, "undeclared" voters -- who in previous elections have boosted the campaigns of politicians who run the ideological gamut from Pat Buchanan and John McCain to Paul Tsongas and Bill Bradley.
Independents represent by far the fastest-growing portion of the New Hampshire electorate, with their numbers up 62 percent in the past decade.
They now represent 44 percent of registered voters in the Granite State -- more than its share of Republicans or Democrats. Under state law, unaffiliated voters can vote in either party's primary, though not in both.
They represent a singular challenge for all the campaigns: How to reach out to a fickle group -- one that shares little in terms of political leanings -- without alienating the party base?
"They really cross the spectrum from left to right on social and economic issues," said Jacqueline Salit, executive director of The Neo-Independent, a magazine for political independents. "Independents want to have a voice. They want to function as a third voice in American politics, not as a third party, but a third voice."
Early polls suggest that undeclared voters are poised to cast their ballots overwhelmingly in the Democratic primary, in large part because of widespread anger over the Iraq War.
Recent polls by the University of New Hampshire Survey Center suggest that between two-thirds and three-fourths of New Hampshire independents expect to vote in the Democratic primary.
That's potentially bad news for Sen. John McCain, R-Ariz., who is hoping to recapture the formula that led him to an upset victory over George W. Bush in the 2000 New Hampshire primary.
That year, 62 percent of independents chose to vote in the Republican primary, powering a dominating win that McCain will be hard-pressed to repeat, said Andrew Smith, director of the UNH Survey Center.
"The McCain people are thinking they'll get them again, because they'd like to replay the 2000 campaign," Smith said. "But it's catching lightning in a bottle."
Independent voters such as Betty Ward, a third-grade teacher who lives in Concord, said they've soured on McCain because they view him as a too partisan a figure now.
Unlike the "maverick" whose trip on the Straight Talk Express won over New Hampshire in 1999 and 2000, McCain's strong support for the Iraq War and President Bush's leadership leaves Ward saying she'll never support him again.
"I can't believe he's the same person," she said.
Ward is typical in many ways of a New Hampshire independent. After supporting McCain in 2000, she volunteered for Democrat Howard Dean in 2004 and voted for him in the primary.
This year she said that while she may be more inclined to vote for a Democrat because of the war issue, her vote is very much up for grabs. Casting a ballot for a Republican is not out of the question if she believes a GOP candidate is hitting the right notes.
"I don't care what you call yourself -- that's irrelevant to me," Ward said. "I look for someone who differentiates himself from the party, someone who will challenge the party, whatever party that is."