A pivotal ruling on mail-in ballots sent without postage has been issued by the Supreme Court of a swing state.

The Nevada Supreme Court ruled Monday that mail-in ballots without a postmark can be received and counted until four days after the election, marking the latest legal setback the court has handed to the Republican Party.

The court has upheld the lower court's decision to reject the Republican National Committee's lawsuit challenging the constitutionality of the post-election deadline for mail-in ballots without a postmark.

The state's decision to count non-postmarked ballots four days after the election, which is the same standard as for postmarked ballots, was challenged by plaintiffs as being "unconstitutional."

Earlier this year, a lower court struck down their injunction to reject the ballots.

The Nevada high court upheld the lower court's decision on Monday, stating that the RNC had not provided sufficient evidence to prove that the non-postmarked ballots were susceptible to fraud or biased towards a specific political party.

The judges concurred with the lower court's viewpoint that the RNC did not have the necessary standing to bring the lawsuit and that the case was speculative in nature.

The majority of justices wrote that it would be against public policy to disregard a properly cast vote by mail if the ballot is not postmarked, even if it is mailed before or on the day of the election.

It is unclear how many residents will be impacted by the decision.

Democrats have positioned themselves as the party that supports free and fair elections by seizing on Republican lawsuits as a means of disenfranchising voters.

Planet Chronicle Digital has reached out to the RNC for comment.