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The Supreme Court will hear a case on Monday that could invalidate hundreds of thousands of votes in the upcoming midterm election. Watson v. Republican National Committee asks the justices to invalidate state laws that count ballots that were mailed on time, but received shortly after Election Day. The GOP argues that federal law requires states to toss all of these ballots—a position that would have nullified more than 750,000 votes in the 2024 election. On this week’s episode of Amicus, co-hosts Dahlia Lithwick and Mark Joseph Stern discussed Watson, its implications for democracy, and its close connection to the SAVE Act—a voter suppression bill pending in the Senate that would impose sweeping new restrictions on mail ballots. An excerpt from their conversation, below, has been edited and condensed for clarity.

Dahlia Lithwick: This is an existential challenge to mail-in voting, and it has arrived just as we have the midterm elections coming up.

Mark Joseph Stern: This case really does drive me crazy. It marks an effort to overturn laws that count mail-in ballots if they arrive shortly after Election Day as long as they are postmarked or scanned by USPS on or before Election Day. About half the states have these laws, including some red states like Texas and Mississippi. They were enacted for the sensible reason that your right to vote shouldn’t be undercut by USPS delays that are outside your control.

Federal law does not say that states have to toss out mail-in ballots that come in after the election. It also doesn’t say that states have to count these ballots. Federal law is entirely silent on this; the only federal statutes that govern the receipt of mail ballots explicitly defer to........

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