RALEIGH, N.C. — A federal judge has halted the enforcement of a North Carolina law that made it a serious crime for someone to vote while still on probation or parole for a felony conviction when they had simply violated the voting law by mistake.

The ruling was celebrated by groups representing poor residents and Black union members – and is limited, addressing some allegations of illegal voting conducted before 2024.

That’s because the General Assembly amended the law last fall so that starting Jan. 1 a felony offender has to know they were breaking the law by voting for there for it to be considered a crime. But the old law had not been repealed.

The plaintiffs in a 2020 lawsuit said that people would still be subject to prosecution for votes allegedly cast before 2024 under the old rules, which didn’t require intentionality to violate them. They said local district attorneys could otherwise still prosecute scores of pending cases.

In her ruling filed late Monday, U.S. District Judge Loretta Biggs said that the pre-2024 law was unconstitutionally vague. She cited evidence in the case of DAs questioning whether intent was necessary as proof that the law lacked standards to prevent its arbitrary enforcement.

And Biggs wrote the pre-2024 law was tainted by racial bias, with its origins going back to the Jim Crow era.

“The Challenged Statute was enacted with discriminatory intent, has not been cleansed of its discriminatory taint, and continues to disproportionately impact Black voters,” Biggs said in granting the motion sought by lawyers for Action NC and the A. Philip Randolph Institute.

There is uncontested evidence of the law originating in an 1877 law that placed harsh penalties on disenfranchised felons, particularly Black residents, Biggs wrote. In recent years, an outsized percentage of Black voters were investigated compared to the percentage of the state’s Black population under the pre-2024 law, she continued.

Government lawyers for the State Board of Elections and for district attorneys who were sued had argued that passage of a new North Carolina Constitution in the early 1970s created “a break from the history” of the law’s otherwise discriminatory past. But Biggs disagreed and pointed out the challenged law was virtually unchanged for decades, from 1931 to 2023.

Biggs’ summary judgment order could be appealed. The state Department of Justice, whose attorneys helped defend the elections board and the DAs, was reviewing the decision Tuesday, a spokesperson said.

The state constitution says a person convicted of a felony can’t vote until their rights of citizenship are restored “in the manner prescribed by law.”

North Carolina law and a recent court ruling state that a convicted felon can’t vote again until they complete their punishments, which include incarceration, probation and other close supervision. Their rights are then automatically restored, but a person must reregister to vote.

The plaintiffs, which are also voter education groups, said that allowing the pre-2024 law to remain in place also would have forced them to use resources to educate ex-felons who were eligible to vote but remained fearful about registering again, in case DAs keep prosecuting people from previous elections.

Biggs’ decision “will help ensure that voters who mistakenly think they are eligible to cast a ballot will not be criminalized for simply trying to re-engage in the political process and perform their civic duty,” Mitchell Brown, an attorney from the Southern Coalition for Social Justice who helped represent the plaintiffs, said in a news release.

Biggs issued the ruling, even as a U.S. magistrate judge had recommended in January that the lawsuit be dismissed, citing the Jan. 1 alteration as substantially diminishing the threat of prosecution faced by prospective voters.

The lawsuit was initially filed in September 2020 but legal hurdles delayed the matter.