Republican efforts to restrict mail-in voting will be debated in a lawsuit over whether absentee ballots must be received (and not just postmarked) by Election Day.
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WASHINGTON – The Supreme Court will consider Republican efforts to restrict mail-in voting on March 23 when it hears a case with far-reaching implications for upcoming midterm elections over whether absentee ballots must be received (rather than just postmarked) by Election Day.
Voting by mail is down compared to its peak during the coronavirus pandemic. However, nearly 30% of voters will still vote by mail in the 2024 election, and many states have grace periods for mail-in voting.
President Donald Trump has long railed against mail-in voting, claiming it risks fraud and making baseless claims that he lost the 2020 election.
“Elections are never honest with mail-in voting. Everyone knows it, especially Democrats,” he wrote in Truth Social in August.
Last year, President Trump signed an executive order overhauling elections, including eliminating the grace period for mail-in ballots received after Election Day. Some Republican-controlled states have changed their rules in response, and Democratic states have so far successfully challenged Trump’s orders in court.
In a separate legal challenge to the Mississippi law, the Trump administration is expected to join the Republican National Committee on March 23 in persuading the Supreme Court to prohibit states from counting mail-in ballots received after Election Day.
The rejection rate for late-arriving ballots is low.
Daniel Thompson, a political scientist at the University of California, Los Angeles, and an expert on how election rules affect outcomes, doubts the incident will have a major impact on the outcome.
She said states without grace periods for mail-in ballots have the same rejection rates for late-arriving ballots as states with more lenient deadlines. Additionally, the overall rejection rate for late-arriving ballots in the 2020 election was less than 1%.
Still, the case (Watson v. Republican National Committee) could influence the public’s perception of election security, said Rick Hasen, an election expert and law professor at the University of California, Los Angeles.
“Mr. Watson falls within this broader pattern of lawsuits surrounding mail-in voting,” Hasen said in a webinar about the case. “I think they are meant to please Trump and make it seem like the election was fraudulent.”
But the case takes an unusual twist in that the law being challenged was passed by a Republican-led Legislature and is being defended by Mississippi Attorney General Lynn Fitch, a Republican.
“Mississippi’s policy choice to only require absentee ballots to be mailed in by Election Day may be opposed by reasonable people,” Fitch said in its Supreme Court filing. “But federal law gives Mississippi the authority to make that choice.”
Most states have a grace period for at least some mail-in voting.
During the COVID-19 pandemic, Mississippi amended its election law to allow absentee ballots postmarked by Election Day to be counted if they are received within five business days.
According to the National Conference of State Legislatures, 29 states allow at least some late ballots cast by U.S. military personnel and Americans living overseas to be counted.
Fourteen states have extended the deadline for counting all mail-in ballots postmarked by Election Day, with Illinois up to two weeks.
Veterans and groups representing veterans worked with the state of Mississippi to defend the grace period.
“Because of Postal Service delays and states not counting ballots received by Election Day, people are being disenfranchised through no fault of their own,” said Marc Elias, a Democratic elections attorney who heads Veterans Voice and the Retired Americans Alliance.
Democrats are also more likely than Republicans to vote by mail, so Republicans are “trying to drive voters out of their districts who don’t want to participate,” Elias said.
Republicans warn of fraud risks
Conservative groups support the Republican National Committee’s argument that strict deadlines are needed to prevent foul play.
“The longer an election is held, the greater the opportunity and risk of fraud,” a number of groups, including gun owners associations, said in a filing.
According to the MIT Election Data & Science Lab, documented cases of fraud related to mail-in voting are rare. A 2025 report from the Brookings Institution estimates that there will be about four incidents of fraud for every 10 million mail-in ballots.
But opponents argue that if votes counted after Election Day affect the outcome of a race, it could raise questions about the legitimacy of the election even if there was no fraud.
“It’s hard to blame Americans for these allegations when results are available quickly in some states, but it takes days to even know how many votes still need to be counted in others,” the Republican National Committee told the Supreme Court.
An incident that changes the definition of “election”
The legal arguments being waged by the RNC and the Department of Justice revolve around the definition of when an election took place, as federal law sets a specific date for U.S. elections.
According to Mississippi, an “election” occurs when voters choose a candidate.
“Voters make their choices by marking and submitting their ballots,” state attorneys said in written arguments. “Therefore, federal Election Day law only requires voters to cast their votes by Election Day.”
Republicans and the Trump administration counter that the election is the day a valid ballot must be received.
“Elections have consequences. Elections also have definitions,” the Justice Department said in its filing. “And since the dawn of America, Election Day has meant the day ballot boxes close and election officials must receive every ballot.”
Mississippi’s federal judges sided with the state, but the New Orleans-based 5th U.S. Circuit Court of Appeals, considered the most conservative appellate court in the country, sided with Republicans.
“Suspicion of fraud”
The Supreme Court touched on this issue in 2020 when it reversed a judge’s order requiring Wisconsin to count late-arriving mail-in ballots during the COVID-19 pandemic.
Justice Brett Kavanaugh wrote in a concurring opinion that one reason the justices erred was because they “failed to fully appreciate the significance of the election deadline.”
Kavanaugh said states that require ballots to be postmarked and received by Election Day “want to avoid the confusion and potential fraud that could occur if thousands of absentee ballots come in after Election Day and potentially overturn the election results.”
Comments in 2020 by conservative judges whose votes could be key to deciding cases suggest sympathy for policy concerns expressed by Republicans. But Kavanaugh has defended states’ right to require all states to receive ballots by Election Day, not that all states must do so.
A carve-out for military voters?
But another consideration for the judges is votes from U.S. military personnel. Justices may be reluctant to block practices that favor military personnel stationed far from home trying to vote.
Still, the high court could do the same as the appeals court and argue that military votes are different because Congress responded with a different law.
Lisa Dixon, executive director of the Election Confidence Center and a consultant to the Republican National Bar Association, said the result is “pretty plausible.”
“The court could certainly treat that as two different categories of ballots,” she said.
