HARRISBURG, Pa. (AP) — The U.S. Supreme Court invalidated a lower appeals court decision Tuesday regarding how rules for mail-in ballots had been applied in a Pennsylvania election, adding an element of uncertainty about voting procedures four weeks ahead of the state’s high-stakes elections for governor and U.S. Senate.

The justices vacated a decision in May by the 3rd U.S. Circuit Court of Appeals that had said mail-in ballots without a required date on the return envelope had to be counted in a 2021 Pennsylvania judge race.

The lower court had said state election law’s requirement of a date next to the voter’s signature on the outside of return envelopes was “immaterial.” That lower court had said it found no reason to refuse counting the ballots that were set aside in the Nov. 2, 2021, election for common pleas judge in Lehigh County.

Those votes were enough to propel the Democrat, Zac Cohen, to victory in the race. He has since been sworn in, and the new U.S. Supreme Court decision is not expected to reverse the results of Cohen’s election contest.

In the latest decision, the justices ruled 7-2 that the Third Circuit must “dismiss the case as moot.”

Joshua Voss, a lawyer who represents the losing judicial candidate in the Lehigh County race, Republican David Ritter, said the effect of the new high court ruling is that state law goes back to where it had been.

“The Department of State certainly should update their guidance,” Voss said. “But at the end of the day, elections are administered by counties and counties will need to assess what the state of the law was.”

In a previously scheduled call on election procedures with reporters on Tuesday morning, acting Secretary of State Leigh Chapman said she had just been informed of the ruling and that “we’re reviewing that decision and we’ll provide guidance to counties accordingly.” Chapman works in the administration of Gov. Tom Wolf, a Democrat.

Chapman released a statement shortly before 2 p.m. regarding the decision.

Acting Secretary of State Leigh M. Chapman issued the following statement in response to today’s U.S. Supreme Court order regarding undated mail ballots:

“Every county is expected to include undated ballots in their official returns for the Nov. 8 election, consistent with the Department of State’s guidance. That guidance followed the most recent ruling of the Pennsylvania Commonwealth Court holding that both Pennsylvania and federal law prohibit excluding legal votes because the voter omitted an irrelevant date on the ballot return envelope. Today’s order from the U.S. Supreme Court vacating the Third Circuit’s decision on mootness grounds was not based on the merits of the issue and does not affect the prior decision of Commonwealth Court in any way. It provides no justification for counties to exclude ballots based on a minor omission, and we expect that counties will continue to comply with their obligation to count all legal votes.”

Acting Secretary of State Leigh M. Chapman

Voss had argued to the Supreme Court that the Third Circuit ruling was already being cited in other cases but should be declared moot.

He said it’s possible that more litigation over the undated envelopes might occur if there is a close race in November and a candidate wants to seek a court review.

“I don’t know about ‘likely’ because it would require a close race. So, possible? Yes. Likely? I don’t know. Remember, these ballots made the difference in Ritter’s race, which is why the case existed,” Voss said.

Pennsylvania allowed only limited use of absentee mail-in ballots until 2019, when a state law OK’d them for voters who did not otherwise qualify from a list of acceptable excuses.

lawsuit by Republican lawmakers challenging the mail-in voting law is pending in state court, while in August the state Supreme Court upheld the law against a separate challenge.

More than 2.5 million Pennsylvanians voted by mail during 2020′s presidential election, most of them Democrats, out of 6.9 million total votes. Chapman said Tuesday that more than 1.1 million absentee and mail-in ballots have been requested for the fall General Election.