A Michigan state judge had ruled last month the former president and 2024 GOP frontrunner can remain on the ballot, arguing Trump had followed state law in entering the presidential race and leaving it to Congress to decide whether he is eligible to serve as president.

While the Constitution specifies the requirements for a presidential candidate to be at least 35 years old and U.S. born, a provision in the 14th Amendment—passed in the aftermath of the Civil War—has been used to challenge Trump’s eligibility in the fallout of the January 6 Capitol insurrection.

That provision states no person can “hold any [state or federal] office” if they have taken an oath of office and “engaged in insurrection or rebellion” against the U.S. government.