The trial over an effort in Minnesota to keep former President Donald Trump off of the 2024 ballot began Thursday at the state Supreme Court as a similar case continued in Colorado.

The lawsuits in both states allege Trump should be barred from the 2024 ballot for his conduct leading up to the Jan. 6, 2021, riot at the U.S. Capitol. They argue Trump’s efforts to overturn the 2020 election results violated Section 3 of the 14th Amendment to the Constitution, which says no one who has “engaged in insurrection or rebellion” after swearing an oath to support and defend the Constitution can hold office.

A group of Minnesota voters, represented by the election reform group Free Speech for People, sued in September to remove Trump from the state ballot under the 14th Amendment provision. The petitioners include former Minnesota Secretary of State Joan Growe and former state Supreme Court Justice Paul H. Anderson.