The Nevada Supreme Court ruled Monday that state officials can accept ballots that arrive without a postmark up to three days after Nov. 5, Election Day.
The court rejected a challenge from the Republican Party. Nevada is considered one of seven battleground states up for grabs between former President Donald Trump and Vice President Kamala Harris.
The court ruled a state law allowing mail-in ballots to be counted if the postmark date "cannot be determined" applied to envelopes with no postmark at all, Bloomberg reported. Republicans had argued that the law should only cover ballots with postmarks that aren't legible, Bloomberg said.
The justices wrote in their decision that the GOP had not offered up claims that ballots without a postmark are susceptible to fraud or that the state lacked tools to address security. They also noted there was no evidence that ballots without a postmark favor one political party.
A spokesperson for the Republican Party did not immediately respond to a request for comment.
"Rejecting timely mail ballots because of postal service omissions cuts against the strong public interest in exercising the right to vote," the majority of justices wrote in the main opinion.
Nevada is the only swing state that accepts late ballots.
Last week, a federal appeals court sided with Republicans by finding a Mississippi law allowing mail-in ballots to be counted if they are received up to five days after an election ran afoul of federal law stipulating when Election Day occurs.
The ruling by the 5th Circuit applies to Mississippi, Louisiana, and Texas.