Donald Trump’s choice for governor of Pennsylvania, state Senator Doug Mastriano, was affirmed last week by Republican primary voters who followed the former president’s order to nominate a candidate who actively sought to overturn the results of the 2020 presidential election.

That may cut it in the fever swamp that is the Pennsylvania Republican Party. But it doesn’t cut it constitutionally.

Mastriano’s actions before, during, and after the January 6, 2021, coup attempt by Trump backers disqualify the newly minted nominee from Pennsylvania’s November ballot, say lawyers who point to a section of the US Constitution that bars insurrectionists and their allies from serving in elected or appointed positions.

Mastriano is a right-wing extremist who has appeared with QAnon conspiracy theorists, trafficked in Islamophobic hate speech, and promised to end public health mandates designed to slow the spread of Covid-19. Like other Trump loyalists, he is also seeking to ban teaching that he thinks is based on “critical race theory” and wants to implement an aggressive program of discrimination against trans youth.

Mastriano is perhaps most known as a fierce advocate for Trump’s Big Lie and a point man for Rudy Giuliani’s on-the-ground efforts to overturn the results of the 2020 election in Pennsylvania, a state Biden won by more than 80,000 votes. After his efforts in Harrisburg were thwarted, the state senator organized busloads of Pennsylvanians to travel to Washington for the “Stop The Steal” rally on January 6, 2021.

Video from the event shows Mastriano crossing police lines outside the US Capitol, which was invaded by Trump backers as part of a violent coup attempt that left five dead and saw 140 Capitol police officers injured. Mastriano claims he did not physically enter the building, but in February of this year he was issued a subpoena by the House committee investigating the insurrection. Noting Mastriano’s public statements, which indicated that he “witnessed ‘agitators…getting in the face of the police’ and…pushing the police up the Capitol steps,’” the chair of the committee, US Representative Bennie Thompson (D-Miss.), wrote, “We would like to better understand these statements and expenditures, events that you witnessed or in which you participated, and communications we believe you may have had with national, state and local officials.”

Mastriano does not seem to be cooperating. But he does seem to be employing alleged insurrectionists on his campaign. NBC News reported last week, “A staffer with Doug Mastriano’s Pennsylvania gubernatorial campaign who helped block media access to an event over the weekend was at the U.S. Capitol on Jan. 6, 2021, when he appeared to smile and laugh as rioters smashed media equipment on Capitol grounds.”

The overwhelming details of Mastriano’s involvement with the coup attempt are such that the watchdog group Free Speech For People has urged Pennsylvania Secretary of the Commonwealth Leigh Chapman to bar Mastriano from the state’s ballot on the grounds that he is disqualified under the US Constitution.

The group points to Section Three of the 14th Amendment to the Constitution, which declares: “No person shall be a Senator or Representative in Congress, or elector of President and Vice-President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof.”

Enacted following the Civil War, the Insurrectionist Disqualification Clause has been in the news in recent months because voters have tried to use it to disqualify several members of Congress from appearing on their state’s ballots, including Representatives Madison Cawthorn (R-N.C.) and Marjorie Taylor Greene (R-Ga.).

Free Speech For People makes a compelling case that the amendment is particularly applicable to Mastriano, as a professor at the Army War College, where he taught strategic studies.

“Mastriano is an experienced military veteran who has studied and written on ‘hybrid warfare’ strategies that relies [sic] on ‘ambiguity’ and disinformation to create instability. Many of these strategies were used during the lead-up to and the execution of the January 6 insurrection,” noted a letter the group sent to Secretary Chapman in March. “In other words, Mastriano was specifically aware of the consequences that his actions and Trump’s actions were likely to have on fomenting and guiding the insurrection and the Stop the Steal movement’s ongoing efforts to subvert the 2020 election.”

Courtney Hostetler, the senior counsel at Free Speech For People, further explains, “When Senator Mastriano engaged in the January 6 insurrection that threatened our democracy and put countless lives at risk, he violated the oath that he made to defend and protect the Constitution. Section 3 of the Fourteenth Amendment is clear: this disqualifies him from running for public office.”