A group of North Carolina voters told state officials on Monday that they want U.S. Rep. Madison Cawthorn disqualified as a congressional candidate, citing his participation in a rally in Washington last January questioning the outcome of the presidential election, which led to a Capitol riot later that day.

Lawyers filed a candidacy challenge against the Republican on behalf of 11 voters with the State Board of Elections, which oversees the process of scrutinizing a candidate’s qualifications. The voters argue that Cawthorn, who formally filed as a candidate for the 13th Congressional District seat last month, is ineligible to run because he violates a U.S. Constitution amendment ratified shortly after the Civil War.

According to the 1868 amendment, no one can serve in Congress “who has previously taken an oath as a member of Congress… to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same.”

According to the written challenge, the events of January 6, 2021 “amounted to an insurgency,” and Cawthorn’s speech at a rally in support of President Donald Trump, his other comments, and information in published reports provide a “reasonable suspicion or belief” that he helped facilitate the insurgency and is thus disqualified.

“It is critical to maintain the bedrock constitutional principle that oath breakers who engage in insurrection cannot be trusted in future office,” said Ron Fein, legal director of Free Speech for People, a national election and campaign finance reform group that is supporting the challenge election.

Fein stated that the Cawthorn challenge is the first of many that they intend to file against other members of Congress involved in the insurgency in the near future. Last week, Free Speech for People and the group Our Revolution announced that they would ask state election officials to bar Trump and members of Congress from appearing on future ballots.

According to the filing, the “leading national precedent” for such cases was established in 1869 by the North Carolina Supreme Court, which defined the meaning of “engage” when it comes to a disqualifying act of insurrection or rebellion under the 14th Amendment.

A text message to Cawthorn and an email to the congressman’s spokesperson seeking comment on the candidate challenge were not immediately returned Monday. According to state law, Cawthorn must “show by a preponderance of the evidence” that he is qualified to run.

Cawthorn, 26, became the youngest member of Congress after winning election in the far-western 11th Congressional District in November 2020, and he has become a social media favorite of Trump supporters. He intends to run in a new congressional district that appears to be more Republican-friendly. He formally filed his candidacy papers with the State Board of Elections last month, just before the filing period was suspended due to redistricting lawsuits.

The challenge requests that the board form a five-member panel comprised of counties within the proposed 13th Congressional District to hear the challenge. The panel’s decision can be appealed to the state board and then to the courts.

The 11 voters are from four counties in the new 13th District, which stretches from the state’s foothills east to parts of Charlotte, according to additional paperwork filed with the board.

Cawthorn stated at the “Save America Rally” on the morning of the riot, just days after being sworn in to Congress, Cawthorn said the “crowd has some fight in it.”

“The Democrats, with all the fraud they have done in this election, the Republicans hiding and not fighting, they are trying to silence your voice,” he added. “Make no mistake about it, they do not want you to be heard.”

Cawthorn voted against certifying Biden’s presidential victory, but later signed a letter congratulating Biden with other Republican members of Congress. Cawthorn claimed he had a constitutional obligation to vote against him. He condemned the Capitol violence, but compared it to the summer 2020 anti-police brutality protests. Nonetheless, Cawthorn warned North Carolinians last summer of potential “bloodshed” over future elections, which he claims will “continue to be stolen,” and questioned whether Biden was “duly elected.”

The challengers also requested that the board allow them to question Cawthorn under oath in a deposition before the regional panel convenes, as well as subpoena him and others for documents.