EXCLUSIVE: DNC joins Supreme Court voting case, blasts RNC efforts as 'wholly un-American'

The Supreme Court agreed in November to take up the case, which could determine the fate of millions of mail-in ballots nationwide.

Breanne Deppisch is a national politics reporter for Fox News Digital covering the Trump administration, with a focus on the Justice Department, FBI and other national news. She previously covered national politics at the Washington Examiner and The Washington Post, with additional bylines in Politico Magazine, the Colorado Gazette and others. You can send tips to Breanne at Breanne.Deppisch@fox.com, or follow her on X at @breanne_dep.

At issue is a lawsuit filed by the Republican National Committee and Mississippi GOP in 2024, which seeks to overturn a state voting law that allows for the counting of late-arriving mail-in ballots that are postmarked on or before Election Day, so long as they arrive within five business days of the election. The RNC and state GOP have argued that they break with federal voting laws — a point vehemently disputed by other states and the DNC. 

In the amicus brief, provided exclusively to Fox News Digital, lawyers for the party urged the Supreme Court to reverse a lower court ruling handed down by the U.S. Court of Appeals for the Fifth Circuit, noting the dozens of states that currently allow mail-in ballots to be counted, so long as they are postmarked before, or on Election Day. They also noted the long history of mail-in ballots in the U.S, which stretches back elections since the Civil War.