It was one of the first claims President-elect Donald Trump made about voter fraud in the wake of his 2016 victory: that his whisker-thin loss in New Hampshire was propelled by thousands of illegal ballots cast by out-of-state voters.

Trump’s revival of that false assertion as he ramps up his reelection campaign is now alarming some New Hampshire Republicans, who fear that the president’s allegations could undermine confidence in next year’s election.

“People hold riots after their favorite football team loses the Super Bowl,” said Fergus Cullen, a former New Hampshire GOP chairman and Trump critic. “There’s just no telling what people will do when they’re incited to it. We’ve never been in a situation like this, where there’s so much dry kindling across the landscape and we’ve got someone all too willing to light the match.”

After losing the popular vote in 2016 by nearly 3 million votes, Trump immediately raised the specter of voting fraud. He alleged without evidence that millions of people voted illegally in California, Virginia and New Hampshire – three states where he lost to Democratic rival Hillary Clinton. He claimed he would have won the overall popular vote “if you deduct the millions of people who voted illegally.”

“Why isn’t the media reporting on this?” Trump asked in a tweet on Nov. 27, 2016.

Shortly after his inauguration, the president announced plans for a commission to investigate alleged voter fraud, which ended up disbanding barely a year later with no findings.

With his reelection campaign now underway, Trump has returned to the topic.

“New Hampshire should have been won last time,” the president told reporters on Aug. 15, en route to a campaign rally in Manchester, “except we had a lot of people come in at the least moment, which was a rather strange situation. Thousands and thousands of people coming in from locations unknown. But I knew where their location was.”

New Hampshire officials have said repeatedly that there is no evidence to support the president’s claim. A review by the New Hampshire secretary of state and the attorney general’s office of all 6,033 voters who cast ballots in 2016 without proof of a New Hampshire address verified the residency of the vast majority of them and led to a handful of inquiries into possible improper voting.

“It is just not accurate” that thousands of out-of-staters voted illegally in New Hampshire, Secretary of State Bill Gardner said in an interview.

Trump’s campaign spokesman, Tim Murtaugh, did not respond to a request for comment.

Some believe the president’s accusations pose a particular threat to New Hampshire’s jealously guarded spot at the start of the presidential primary schedule if he undermines national confidence in the integrity of state elections and prompts scrutiny of whether that role should continue. In turn, the retail politicking the small state demands could give way to expensive campaign advertising in a bigger state.

“That could ultimately cost our place in the process,” said Josh McElveen, a New Hampshire consultant for both parties who is currently advising Don Bolduc, a Republican candidate for U.S. Senate. “I think that would be bad for New Hampshire, and I think it would be bad for the country. It would only make money more influential.”

New Hampshire allows same-day registration, meaning a voter can walk into a polling location on Election Day and register and cast their ballot all at once.

Thousands of voters show up at the polls without the proper proof that they are eligible to vote. In those cases, voters are required to sign an affidavit attesting to their eligibility.

Over the years, state elections officials have fielded claims that out-of-state voters are taking advantage of same-day registration on Election Day.

Randal Heller, a political activist from Barrington, New Hampshire, is an independent who voted for Trump in 2016. He said he overheard college students waiting for a polling location to open and worrying that their photograph might be taken. Heller said he shared his concerns with state Republicans.

“It raises suspicion that perhaps they are not entitled to be voting in the state of New Hampshire,” said Heller, who is 66 and a retired Naval officer.

But officials have not found evidence to support such allegations.

Gardner – a Democrat who was a member of Trump’s now-disbanded voting fraud commission – said he has received calls from voters reporting dozens of people pouring out of buses with Massachusetts tags and filing into voting locations. He said he has never found evidence of wide-scale illegal voting; one time, he learned after following up on such a tip that the bus was filled with political science students from Wellesley College who had driven up with their professor to observe New Hampshire’s first-in-the-nation primaries.

“You’ve got thousands of people at polling places with phones, with cameras, and nobody has a videotape,” said Cullen, the former state GOP chair. “I’m reminded how there used to be sightings of Bigfoot and aliens all the time.”

Kathy Sullivan, a former state Democratic Party chair, said the accusations first surfaced when Democrats started winning statewide races regularly.

“It was as if New Hampshire Republicans couldn’t believe that New Hampshire could vote for Democrats,” Sullivan said. “So they started claiming that we were bussing people in from Massachusetts, which of course is a made-up thing.”

Gardner’s office, along with the attorney general’s office, reviewed all the voter affidavits signed during the 2016 election. State officials confirmed the eligibility of the vast majority, pursing only four cases of potential wrongful voting, according to their report.

One resulted in a fine. Three were dismissed after investigators determined the voters had attempted to register during hospital stays, according the attorney general’s office.

Using a multistate database, state officials also scrutinized potential instances of duplicate voting in New Hampshire and elsewhere, resulting in five prosecutions. One resulted in a guilty plea for fraud, while four cases are ongoing, the attorney general’s office said.

State GOP leaders have stopped short of endorsing Trump’s claims, but they cited the potential for out-of-state voting when they passed a law last year requiring voters to comply with strict residency requirements such as getting a New Hampshire driver’s license and vehicle registration. Critics have argued in a pending lawsuit that the law unfairly targets college students with the equivalent of a poll tax.

Republican supporters said that until the measure passed, college students from out-of-state were allowed to vote in New Hampshire without establishing the state as their legal residence.

“Look, they didn’t steal it because the laws allowed them to,” Gov. Chris Sununu said in an interview on the Howie Carr Show in January, referring to the 2016 victories of Clinton and Democratic Sen. Maggie Hassan in the state. “We had these very gray, amorphous laws that allowed it to happen. Did they do anything illegal? No, I don’t think they did anything illegal. I think we just had these loopholes that existed, and they exploited it.”

Sununu added that if the state’s college students hadn’t been allowed to participate in the election, Trump and then-Sen. Kelly Ayotte would have won “by a landslide. Yeah. It’s not even close. Not even close.”

He said the new law “fixed” the problem – a statement that Democrats have seized upon as evidence that the law’s real intention is to discourage New Hampshire college students from voting.

Some Republicans who find Trump’s rhetoric problematic nevertheless defend the new law.

“I don’t want to limit anybody’s right to vote, but I also think that it’s a legitimate thing to protect, to ensure that only those people who do have a legal right to vote are the ones voting,” said Jennifer Horn, a former state GOP chair and frequent Trump critic.

But she added: “We’ve turned something that should be a basic American ideal into a partisan issue, and I think that’s a shame. And I think this president has figured out very quickly how to take advantage of that.”

In the radio interview, Sununu, an avid Trump fan, indicated the president is fixated on the issue of voter fraud in New Hampshire. “Oh, trust me, he’s asked me every time” they speak, the governor said.

Trump’s landslide victory in the New Hampshire primary in 2016, which boosted his campaign after he had lost the Iowa caucuses to Sen. Ted Cruz (R-Tex.), has shaped his complicated relationship with the state.

After Clinton won the state in the general election by 2,736 votes – less than one-half of a percentage point – Trump immediately questioned the results.

Corey Lewandowski, Trump’s former 2016 campaign manager, who is considering a bid for the U.S. Senate in New Hampshire, said the new residency law will make a difference for Trump as well as the GOP Senate nominee next year.

“You can’t just walk into the state of New Hampshire anymore with a Massachusetts, Vermont or Maine ID and say, ‘I want to vote,’ ” Lewandowski said in an interview. “It was ripe for voter fraud, and the legislature addressed that.”

Asked if he was aware of any instances of such fraud, he said: ‘If one person votes illegally in the state, it’s one person too many.”

The Washington Post’s Alice Crites contributed to this report.

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