The Trump campaign and its allies filed a lawsuit Friday challenging a Nevada law allowing elections officials to accept mail ballots for up to four business days after Election Day, as long as they are postmarked before polls close.

The lawsuit alleges that the four-day period for mail ballots to be received violates federal law because it does not conform to the Election Day deadline established by the federal government. Attorneys for the plaintiffs, which include the Republican National Committee and the Nevada Republican Party, argue that the law establishing the ballot timeline is therefore “unlawful and must be enjoined.”

“The result of Nevada’s violation of federal law is that timely, valid ballots are diluted by untimely, invalid ballots, which violates the rights of candidates, campaigns, and voters under federal law,” attorneys wrote in the lawsuit filed in federal district court in Nevada.

Nevada adopted a largely all-mail voting system in 2021, permanently codifying pandemic-related election changes adopted for the 2020 election season. The legislation was staunchly opposed by Republicans and passed on party lines out of both the Assembly and Senate. 

The legislation reduced some of the deadlines that were implemented during the 2020 election — shortening from seven to four days the timeframe after an election when mail ballots postmarked by Election Day can be accepted. There is a reduction of seven to six days in time for voters to fix issues on their mail ballot (a process called “signature cure”). 

Nevada is one of eight states that allow elections to be conducted entirely by mail. These include California, which allows mail ballots to be received no later than three days after Election Day, Oregon, which counts ballots received up to seven days after Election Day, and Utah, which only requires that ballots be postmarked by the day before Election Day.

Secretary of State Cisco Aguilar said in a statement that the secretary of state’s office will not comment on ongoing litigation, “but I hope the RNC is putting as much time and energy into educating voters on how to participate in elections as they put into suing the state of Nevada.”

Aguilar added that Nevada runs some of the most secure, transparent and accessible elections in the country. The key to that accessibility, he said, is allowing Nevadans to choose what voting method works best for them, including mail.

In a conversation about the future of Nevada’s elections with The Nevada Independent CEO Jon Ralston at a Thursday event hosted by UNR and The Atlantic, Aguilar said the adoption of mail ballots has increased since it was first implemented in 2020 and the state needs to increase the capacity of counties to process mail ballots.

With the deadline for accepting mail-in ballots falling four days after Election Day, complete results are not as immediately available as in the past. Nevada’s status as a purple state can often mean narrow vote margins where every ballot could make the difference between a win or a loss for candidates, so media outlets and other observers sometimes wait days to declare a winner in certain races.

The more time it takes to issue results, Aguilar said, the more opportunity there is for false narratives, even though there is no evidence of widespread fraud in Nevada’s election system.

“We’re a purple state, we’re a battleground state, we have extremely competitive elections and the accuracy of those elections is critical,” Aguilar said, adding that there’s a rigorous signature curing and review process for each ballot.

Updated at 1:50 p.m. on 5/3/2024 with a statement from Aguilar.