In PA, MN, and TX, federal judges have ordered election officials to "segregate" certain ballots.
The vote-by-mail ballots that arrive late are being set aside in case another court invalidates them.
Around 127,000 votes that were cast at drive-thru locations in TX during the early voting period.
Those ballots have been specially marked for the same reason, says Business Insider.
All of these court orders came after extensive litigation and it's not clear how many votes are at risk.