On Tuesday, students packed into an auditorium at Dartmouth College for a town hall event with Sen. Kamala Harris (D-CA), as she traveled through New Hampshire to pitch voters on her campaign for president.

Garrett Muscatel, a 20-year old Dartmouth student who also happens to be a New Hampshire state legislator, introduced Harris at the event. Afterward, as his classmates filed out, he spoke to The Daily Beast and pointed out a problem: only himself and “a couple out of everyone who’s here” will end up voting in the state’s pivotal first-in-the-nation primary.

“Because the Republicans passed legislation to make it so that college students couldn’t vote without paying a poll tax, ” he explained.

The law in question imposes new burdens on voting for residents who hail from out of state and has been at the center of political debate in New Hampshire since it was signed into law last year by Republican Gov. Chris Sununu. With the 2020 primary heading into full swing, the law is now drawing national attention for how it could impact access to the polls for a significant voting bloc—college students—in a politically significant state.

On Monday, Sen. Jeanne Shaheen (D-NH), sent a letter to all the presidential candidates calling on them to condemn the law. At least eight of them did so promptly. At a CNN town hall in Manchester on Monday night, Sen. Bernie Sanders (I-VT) blasted the “cowardly” Republican governors pushing laws making it more difficult for young people to vote. “Students are the ones who will have to deal with the decisions lawmakers make for decades to come,” tweeted Sen. Cory Booker (D-NJ), who is making frequent visits to New Hampshire. “Protecting their right to vote is paramount.”

In the past, prospective voters in New Hampshire only had to prove that they lived somewhere in the state to be eligible to vote. The legislation, referred to in New Hampshire by its legislative shorthand, H.B. 1264, establishes more stringent residency requirements, requiring prospective voters to get a state driver’s license and car registration if they want to vote in New Hampshire.

Under the new law, to vote without taking those steps warrants a misdemeanor charge. The law is set to take effect in July.

Muscatel, the student state legislator, ran for office 2018 with a focus on voting rights. Originally from California and now a New Hampshire resident, he described what it would take for out-of-state college students like him to vote without running afoul of the new law: a 40-minute drive to the nearest DMV, $50 to apply for a license, up to $300 to register your car if you own one.

“Starting in July,” Muscatel says, “it’s going to be very difficult for students to cast their ballot.”

The voting rights fight over H.B. 1264 is the latest one sparked by New Hampshire Republicans, who pushed a similar bill in 2017 that threatened $5,000 fines if voters’ registration information was incorrect.

The GOP has argued that the state needs to tighten up its voting requirements. Previously, New Hampshire was the last state in the country not to have some kind of permanent residency requirement to vote; Sununu has argued that H.B. 1264 is a common-sense measure that strengthens the integrity of the state’s elections.

Speaking in January with Howie Carr, a widely-listened conservative talk radio host in New England, the governor declared, “We took care of it.”

“We quote unquote fixed the problem. Closed the loophole. Got some certainty back into our system. And when you're the first in the nation primary, there's a real responsibility to have a system with integrity.”

But states define residency in different ways—and only some states, such as California, link voting to motor vehicle laws, like H.B. 1264 proposes doing.

But, according to Paul Twomey, a veteran New Hampshire election lawyer, “no state ever changed its motor vehicle regulations for the sole purpose of keeping a discrete group of people from voting.”

Beyond that, longstanding claims about voter fraud in New Hampshire have cast Republicans’ arguments about election integrity in a more political light. Rumors of widespread voter fraud in the state got a massive amplification from President Donald Trump, who has fixated on the idea that busloads of people came in from neighboring states in the 2016 election to swing New Hampshire for Hillary Clinton by just 3,000 votes. Fact-checkers, along with the Democratic secretary of state, have not found any evidence for this claim.

In another appearance with Carr, himself a Trump pal, Sununu said that the president raises the specter of voter fraud in New Hampshire every time he sees him. The governor told Carr that without the Democratic votes from college towns, “then Trump and [former Sen. Kelly] Ayotte win by a landslide. Yeah. It’s not even close.”

To Democrats, this comment lays bare Republicans’ true intentions: discouraging a reliably left-leaning voting bloc from going to the polls. College students account for roughly 90,000 of the state’s 1.2 million residents; even at the University of New Hampshire, the state’s largest university and its flagship public institution, half of all students come from out of state.

Lucas Meyer, president of the New Hampshire Young Democrats, says there are still fundamental questions about how the state will enforce the new law.

“It’s confusing and complicated, which I think is the point,” Meyer told The Daily Beast. “These election law changes get dropped in at the state house, and then regardless of what the intent of the bill was, we hear from students on campus who now think ‘oh, I can’t vote’, so we have to be diligent about continuing to educate students on their constitutionally protected right to vote."

There are several challenges to the new law, casting some doubt over whether it will be on the books when New Hampshire votes next year. Bills to repeal it, or carve out an exception for college students in the new residency requirements, could earn passage out of the Democrat-held state legislature. Most believe Sununu will veto those bills, leaving it up to the courts to decide whether the law violates voting rights.

Last year, the state Supreme Court upheld the constitutionality of the law on a 3-2 vote, with the majority arguing it simply forced people to choose between voting in another state or voting in New Hampshire and meeting state residency requirements. But the American Civil Liberties Union has filed a lawsuit against the state on behalf of two Dartmouth students, claiming HB 1264 is unconstitutional.

No matter what ultimately happens in court, the chilling effects of the law on voter participation in New Hampshire are already on display as presidential candidates travel through the state, courting young voters who might cast a ballot somewhere else.

In the audience for Harris’ town hall at Keene State College on Tuesday was Nathaniel Jarvie, a 20-year old student originally from Connecticut. He went back to Connecticut to vote for the 2018 elections, and said he’d probably do so again in 2020 to avoid confusion or penalties.

“I’d be more tempted to vote here,” he said, “if they got rid of the stupid law.”