Mitchell said voters who meet the legal requirements should not lose their votes because officials failed to deliver ballots on time. Wisconsin law says ballots must be delivered to polling places by 8 p.m. on Election Day, but the judge found that official error is not a lawful reason to reject a ballot already in the clerk’s custody by the deadline.

The decision follows a dispute over 23 Madison ballots in Wisconsin’s April state Supreme Court race. The city had the ballots before Election Day, but they did not reach polling places by 8 p.m. City officials said an election administrator’s error caused the delay. In May, Mitchell ruled that Madison was right to count the ballots after the Wisconsin Elections Commission had ordered that they not be counted.

Margaret and Robert Honig, two of the voters whose ballots were delayed, filed the lawsuit. They argued that rejecting properly cast votes because of officials’ mistakes would violate voters’ constitutional rights. The commission maintained that state law’s 8 p.m. delivery deadline bars counting ballots that arrive later. Dane County Clerk Scott McDonell argued that the law should not penalize voters for errors made by election officials.

The ruling sets a clear limit: It does not extend the deadline for voters to return ballots, and it does not allow late-arriving ballots to be counted if a voter was even partly responsible for the delay.

Ann Jacobs, a Democratic appointee to the Wisconsin Elections Commission, welcomed the decision. “The errors of the clerk should not be visited upon innocent voters,” she said. Commission Chair Don Millis, a Republican, did not immediately respond to a request for comment.

Scott Thompson, staff counsel at Law Forward, which represents the Madison voters, called the decision “a major victory for voting rights in Wisconsin.”