A liberal group filed a lawsuit Tuesday to block former President Donald Trump from the 2024 presidential ballot in Minnesota, the second major lawsuit in two weeks that hopes to invoke the 14th Amendment’s arcane “insurrectionist ban.”

The cases are seen as legal long shots. Trump denies wrongdoing and has vowed to fight to remain on the presidential ballot. The new Minnesota lawsuit was filed in state court by Free Speech For People, one week after another group initiated a similar challenge in Colorado.

A post-Civil War provision of the 14th Amendment says any American official who takes an oath to uphold the US Constitution is disqualified from holding future office if they “engaged in insurrection or rebellion” or have “given aid or comfort” to insurrectionists.

However, the Constitution doesn’t spell out how to enforce this ban, and it has been applied only twice since the late 1800s, when it was used against former Confederates.