And suddenly, Haley and Christie are encountering independent voters at their town halls who may not vote in the Republican primary after all.

“I would like to hear Dean Phillips,” Larry Gray, a Newcastle independent, said about an hour after telling Christie at a recent business roundtable that he was backing the former New Jersey governor.

Diane Noble, a Nashua independent who’s interested in Haley and Christie, said at a town hall for the former South Carolina governor that she’ll “absolutely” be doing her due diligence on the Democratic side now that Phillips is in.

“If Dean Phillips runs the kind of race that he says he’s going to run … then all independents will be up for grabs,” said Mike Dennehy, a veteran GOP operative in New Hampshire.

And that, he said, is “harmful to Chris Christie and to Nikki Haley.”

It’s difficult in this notoriously late-breaking state to predict the extent to which a Democratic contest — and a messy one, with Biden not on the ballot and his allies running a write-in campaign on his behalf — will affect Haley and Christie’s vote counts. And Christie is dismissing Phillips as a threat to his chances in the state where both candidates are staking their campaigns.

“Dean Phillips doesn’t really concern me at all. I think we’ll be fine,” Christie told reporters after a recent campaign stop in Derry. “The Republican primary is a much more attractive option for stopping Donald Trump, and I think that’s what a lot of independents want to do.”

But both Christie and Haley have been rising in recent polls of the first primary state in no small part because of the support they’re earning from independents. Polling averages now show them in second and third place, respectively, in New Hampshire, where even a marginal shift in the electorate could alter the trajectory of their campaigns.

Independents make up just over 39 percent of the state’s voters with Republicans and Democrats both around 30 percent. More than 3,500 Democrats switched to unenrolled — New Hampshire’s term for independents — ahead of the state’s early October deadline to change party affiliation for the Jan. 23 primary.

Pro-Christie groups had urged Democrats to switch ahead of the deadline. Now, both Phillips and the Democrats running the Biden write-in effort say they’re looking to pull independents back to their side.

“This gives independents now a chance to focus on where they want to cast their ballots,” Jim Demers, one of the architects of the Biden write-in effort, said in an interview. “Knowing that Donald Trump in all likelihood is going to win here in New Hampshire, I think there may be some independents who are rethinking about ‘maybe I’ll write in Joe Biden’s name instead.’”

Phillips is already drawing some independent support at the margins. Nine weeks out from the 2024 primary in New Hampshire, a University of New Hampshire/CNN poll showed 10 percent of independents likely to vote in the Democratic contest would cast ballots for the Minnesota lawmaker, compared to 61 percent who said they would write in Biden’s name.

Independents have a long history of changing the course of presidential primaries in New Hampshire. They boosted Ron Paul and Jon Huntsman to second and third place, respectively, in the 2012 GOP primary. Exit polls also show they helped hand Trump his first primary win in 2016 and powered Bernie Sanders over Hillary Clinton on the Democratic side that year.

This year, it’s Haley and Christie who appear to be benefiting the most from independents’ interest as they vie to be the main contender against the former president. A University of New Hampshire/CNN poll of 994 likely Republican primary voters showed Haley with 25 percent support among independents and Christie and Trump with 24 percent apiece. No other candidate got above 15 percent support from independents in the online survey conducted Nov. 10-14.

A recent Monmouth University/Washington Post poll showed similar results. Christie was pulling 35 percent support among respondents who identified as independents or Democrats. Haley was at 31 percent among that group. Trump trailed at 12 percent. The poll of 606 potential New Hampshire GOP primary voters was conducted online and by phone from Nov. 9-14. Haley’s campaign did not respond to a question about how it’s assessing the Phillips factor, though spokesperson Ken Farnaso said, “Nikki is the best challenger to beat both Donald Trump and Joe Biden.”

But if the Democratic primary becomes more competitive, both Haley and Christie could suffer. David Paleologos, the polling director at Suffolk University in Boston, said that’s especially true of Christie, a fierce Trump critic who is drawing support from independent voters in New Hampshire who primarily lean Democratic.

“Christie’s support in New Hampshire may be smaller than it seems,” Paleologos said, “because those voters might just enter in the Democratic primary.”

In interviews with nearly a dozen independent voters across campaign events for Phillips, Christie and Haley over the past few weeks, some were thinking of doing just that.

“I’m panicked that [Biden] might get nominated, we don’t want that. But we also don’t want it to be Trump versus Biden, because we don’t want either of them,” Dale Boyle, a Nashua independent, said at a Christie town hall in the city this week.

Boyle still feels she’ll have more impact voting in the GOP primary. But Phillips is turning some other independents’ heads to the left.

Colin Reynolds, an independent from Manchester, said he was considering voting for Haley and that Christie “might be second on my list.” But he was curious enough about Phillips that he came to see him at a town hall.

“I’m interested in the idea of a Democrat running against Biden,” he said.

Steven Shepard contributed to this report.