DENVER (AP) — Court arguments have begun in the efforts to use an insurrection clause in the U.S. Constitution to bar former President Donald Trump from running for his old job again.

Testimony on Monday is focusing on whether the violent Jan. 6, 2021, assault on the U.S. Capitol was an insurrection as defined by the 14th Amendment and whether Trump’s role in it meets the provision’s threshold for being barred from public office.

Trump’s attorney calls the case “anti-democratic.”

Later in the week, the Minnesota Supreme Court will consider the same issue for that state’s ballot.

The nation’s highest court has never ruled on the clause, which was added after the Civil War.