The Gwinnett County Board of Voter Registrations and Elections on Monday morning denied a challenge of more than 15,000 voters’ eligibility to cast a ballot in the Jan. 5 runoff vote.

The voter challenge was part of a statewide effort to force more than 364,000 voters to prove their eligibility to participate in the runoff. The organization True the Vote has supported challenges in every Georgia county with only two weeks until election day.

Had it gone forward, the challenge would not have permanently removed the 15,201 voters from Gwinnett’s rolls, but forced them to prove that they still live in the county in order to vote in the runoff. The county has nearly 590,000 active registered voters.

The list of voters presented to the elections board by BJ Van Gundy, who identified himself as a representative of the Georgia Republican Party, was made up of people who had filed a change of address form with the U.S. Postal Service, indicating they were moving from a Gwinnett address to another state.

Voters temporarily living in another state for purposes including work, school or a temporary personal obligation like caring for a loved one are still eligible to cast a ballot at their permanent address in Georgia. Change of address forms do not necessarily indicate a permanent move; they help the USPS redirect a person’s mail when that person will be residing elsewhere for an extended period of time, whether temporarily or permanently.

The Gwinnet elections board voted 3-2 to deny the challenge, with Republican board members Alice O’Lenick and Ben Satterfield voting against the denial. Democratic board member Stephen Day said the request was impractical and potentially illegal.

“This is nightmarish from an adjudication standpoint, a practical standpoint,” he said. “I think that this is ill-conceived and ill-timed and violates the law in many places.”

O’Lenick, who has expressed concerns about elections security in the county previously, said the challenge was evidence Gwinnett’s voter rolls are “not pristine” and may need additional review.

A similar challenge in Cobb was also denied on Friday. True the Vote has had one successful challenge in Muscogee County, where about 4,000 voters will now have to prove their eligibility if they want to cast a ballot in the runoff.