South Carolina law allows voters who are 65 and older to vote by mail without any particular excuse, but denies younger voters the same opportunity. South Carolina voters who are under 65 challenged this scheme on the ground that the express discrimination between adult voters of different ages violates the Twenty-Sixth Amendment to the U.S. Constitution, which promises that the right to vote of all citizens eighteen and older “shall not be denied or abridged” by any state “on account of age.” 

The United States District Court for the District of South Carolina upheld the state’s age-based restriction on mail-in voting, holding that the Twenty-Sixth Amendment’s constitutional prohibition on age discrimination in voting does not protect younger voters from facially discriminatory absentee voting laws. In August 2025, CAC filed an amicus curiae brief urging the Fourth Circuit to reverse the district court’s ruling.  

Our brief explains that the text and history of the Twenty-Sixth Amendment prohibit laws that deny equal voting opportunities to adult voters on account of age. Going beyond simply extending the right to vote to those 18-21 years old, the broad language of the Twenty-Sixth Amendment expressly forbids age discrimination in voting in the same manner the Fifteenth and Nineteenth Amendments outlaw discrimination in voting on the basis of race and sex. Indeed, our brief shows that the Twenty-Sixth Amendment was intentionally modeled on the Fifteenth and Nineteenth Amendments. As a result, the Twenty-Sixth Amendment forbids the government from curtailing or diminishing the rights of any adult voter on account of age. In the same way that voting laws may not limit mail-in voting to just men or just white people, they may not limit mail-in voting to just voters who are 65 and older. 

The brief also argues that the district court was wrong to rely on Fourteenth Amendment precedent that predated the ratification of the Twenty-Sixth Amendment to guide its interpretation of the meaning of the “right to vote” in the Twenty-Sixth Amendment.  In doing so, the court ignored the constitutional transformation the Twenty-Sixth Amendment wrought. The Twenty-Sixth Amendment was necessary precisely because the Supreme Court had ruled in an earlier case that the Fourteenth Amendment did not allow Congress to lower the voting age to 18 in state elections. The district court erred when it disregarded this critical context and weakened the Twenty-Sixth Amendment’s age-based protections for voters over 18.