Georgia Secretary of State Brian Kemp, who has faced allegations of voter suppression in the state’s gubernatorial contest in which he is the Republican nominee, encountered some voting problems of his own when trying to cast a ballot on Tuesday.

According to Atlanta-based WSB-TV reporter Dave Huddleston, a machine told Kemp his voter card was “invalid” when he tried to cast a ballot at his local polling place. Kemp went back, got another card and cast his ballot, the station reported.

GOP gubernatorial candidate Brian Kemp also had a voting issue today. When he tried to vote, his voter card said "invalid." Our @DaveHWSB was with Kemp today as he voted and is covering the campaign all night. #ElectionOn2 https://t.co/d4yktfco6v pic.twitter.com/YR9FeJUijj — WSB-TV (@wsbtv) November 6, 2018

Parts of Georgia were beset by voting problems on Tuesday. In suburban Atlanta, voters waited more than four hours to vote at an elementary school where some voting machines were not working at the start of the day.

Kemp has come under fire for his dual role as state election overseer and Republican gubernatorial nominee, with figures such as former president Jimmy Carter calling for him to step down as secretary of state to preserve the independence of Georgia’s election process.

Democratic nominee Stacey Abrams, who would become the nation’s first black female governor if elected, has called Kemp an “architect of voter suppression for the last decade” and argued he has “tried to steal the right to vote from 53,000 Georgians.”

Kemp has declined to step down and has maintained that such criticism amount to little more than a “publicity stunt” by Abrams’s campaign.