New Hampshire Republicans are advancing a measure to tighten residency requirements to vote in the state, a move critics say unfairly targets college students and other people who may live in the state for a long time, but don’t intend to remain there permanently.

The measure is significant because there has been continued interest in residency requirements to vote after President Donald Trump claimed repeatedly he would have won the state in the 2016 presidential elections had thousands of people not been bused in illegally, a claim for which he has offered no evidence.

New Hampshire law defines residents and eligible voters differently. To vote, a person only needs to be “domiciled” in the state, meaning they live there and intend to remain there for an indefinite amount of time. To be a resident, someone needs to intend to remain in the state permanently. Once someone becomes a resident, they have to get a New Hampshire driver’s license and register their car in the state.

On Tuesday, New Hampshire Republicans in the state Senate advanced a measure out of committee that would do away with that difference and only allow residents to vote. Critics say the measure imposes unnecessary additional barriers to voting because anyone who chooses to register would be forced to pay fees to get a driver’s license and register their vehicle, consistent with the residency requirements.

“When a college student registers to vote, they shouldn’t be threatened with possible legal penalties for how their car is registered. Voter registration should be a simple, straightforward process for all eligible Granite Staters,” Jason Kander, the former Democratic Missouri Secretary of State and president of Let America Vote, said in a statement. “This is classic voter suppression, and it’s clearly a Republican priority to stop college students in New Hampshire from being able to vote in the state where they spend the most time.”

Gilles Bissonnette, legal director of the ACLU of New Hampshire, said the lawmakers wanted to impose what constituted a “post-election poll tax.”

Sen. James Gray (R), one of the senators who introduced the measure, told the Concord Monitor the vehicle registration and driver’s requirements were just consequences of residency.

“If you’re a resident, if this is the place you choose to live abandoning all others, I want you to vote in New Hampshire. But if that place you choose to interact with is in Massachusetts, in Vermont, in Maine, in Kalamazoo, New Mexico, then I want you vote there,” he told the paper.

The GOP bill will be taken up by the full state Senate in January.

New Hampshire Gov. Chris Sununu (R) signed a law earlier this year requiring people who recently moved to the state to show proof they intended to stay there when they registered. Democrats sued the state over the law and a state judge ruled in September officials could not punish people for failing to provide that proof.

In 1974, the New Hampshire Supreme Court ruled that students could not be blocked from voting just because they intended to leave the state at some point in the future.

The debate over who can vote in New Hampshire has even more urgency because of the razor-thin margins that decided the 2016 elections for president and U.S. Senate in the state. Hillary Clinton defeated Trump by 2,732 votes and Sen. Maggie Hassan (D) defeated Republican incumbent Kelly Ayotte by just over 1,000 votes. Trump said repeatedly people from out of state were bused in on Election Day and determined those results.

Kansas Secretary of State Kris Kobach (R), who is the vice chair of a commission Trump convened to investigate voter fraud, also stoked fears about non-residents voting. In September, he authored a column in Breitbart saying he had “proof” the 2016 election was swung by out-of-state voters, citing thousands of people who had registered with an out-of-state driver’s license and subsequently didn’t get an in-state one. He failed to mention, however, that state law didn’t require people who voted to obtain a driver’s license.

Ray Buckley, the chairman of the New Hampshire Democratic Party, said Republicans were trying to stir up concerns over voter fraud in an effort to justify more restrictive voting.

“For years, Republicans have been slowly eroding voting rights in New Hampshire. HB 372 would effectively disenfranchise thousands of legal Granite State voters. New Hampshire Republicans like Governor Sununu and Senator Birdsell have been trying to trick New Hampshire voters into believing there is widespread voter fraud to create a pretext for voter disenfranchisement legislation that would help swing elections in their favor,” Ray Buckley, the chairman of the New Hampshire party said in a statement.