Hundreds of Republican and unaffiliated voters in Colorado are among the nearly 4,000 people who have canceled their voter registrations in the wake of the Trump administration’s request for voter information.

The Colorado Secretary of State’s Office reported Monday that of the 3,738 people who withdrew their registrations between June 28 and Friday, 367 are Republicans and 1,255 are unaffiliated voters. Just over 2,000 Democrats have also canceled their registrations.

The cancellations are just a minuscule fraction of the state’s 3.7 million registered voters. But the figure is striking nonetheless, with some county election officials reporting that they’ve never seen anything quite like it in their careers.

The withdrawals began in earnest earlier this month, after a presidential advisory commission on election integrity requested publicly available voter information from all 50 states. On July 10 alone, 1,237 Colorado voters withdrew their registrations.

It’s my hope that folks who withdrew their registration will reregister. #copolitics pic.twitter.com/t3reINP3S3 — Wayne Williams (@COSecofState) July 17, 2017

Another 200 Colorado voters have signed up to become “confidential voters,” a designation that allows their information to be withheld.

President Donald Trump established the advisory commission in May with a mandate to review U.S. election integrity, with a focus on voter fraud, voter suppression and other “vulnerabilities.” But the effort has been clouded by privacy concerns and distrust from the start.

Colorado Secretary of State Wayne Williams, along with dozens of other secretaries of state across the country, has said he will provide only information considered public under Colorado law, a category that includes voters’ names, addresses, party affiliations, birth years and which elections they have participated in.

The commission’s request is on hold while a legal challenge plays out in court.

On Friday, Williams sent a letter to the commission saying the state’s election system works well and that a blanket request for voter information isn’t an effective way to seek out fraud.