The Supreme Court just undid a key ruling for counting undated Pennsylvania mail ballots
Chester County elections workers preparing mail ballots for processing during the 2020 vote count. - JOSE F. MORENO/The Philadelphia Inquirer/TNS

The U.S. Supreme Court on Tuesday vacated a federal appeals court decision that had allowed undated mail ballots to be counted in Pennsylvania, injecting new uncertainty into an issue that could affect thousands of votes in next month’s elections. The decision, which vacated a key ruling from the Third Circuit Court of Appeals, will open the door for new lawsuits over an issue that has become a consistent political and legal fight over the last two years. Republicans are likely to file new litigation arguing that undated mail ballots should be rejected, while Democrats will continue to fight f...