People who take part in insurrections against the US government can be barred from office, an appeals court said on Tuesday, reversing a ruling in favor of Madison Cawthorn, an extremist Republican politician from North Carolina.

Hailing a “major victory”, Free Speech For People, the group which brought the case, said: “This ruling cements the growing judicial consensus that the 1872 Amnesty Act does not shield the insurrectionists of 6 January 2021 – including Donald Trump – from the consequences of their actions.”

Cawthorn lost a primary this month and will not return to Congress in November. But Free Speech For People pursued an appeal.

It also brought cases against Marjorie Taylor Greene of Georgia, two Arizona Republicans, Paul Gosar and Andy Biggs, and an Arizona state representative, Mark Finchem. All have been unsuccessful.

The challenges cited the the 14th amendment to the US constitution, passed after the civil war.

It says: “No person shall … hold any office, civil or military, under the United States, or under any state, who, having previously taken an oath … 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.”

Cawthorn and the other Republicans were closely tied to events around the deadly January 6 attack on the US Capitol by Trump supporters seeking to stop certification of Joe Biden’s election victory. They have denied knowledge of plans for violence.

In answer to Free Speech for People, lawyers argued that an 1872 amnesty law for former Confederates did not only apply retroactively. Judges sided with them.

Ruling in the Cawthorn appeal, Toby Heytens, one of a three-judge panel of the US court of appeals for the US fourth circuit, wrote: “The available evidence suggests that the Congress that enacted the 1872 Amnesty Act was, understandably, laser-focused on the then-pressing problems posed by the hordes of former Confederates seeking forgiveness.”

Heytens also said only Congress could decide such matters, writing: “When the district court here tried to determine the effect of the 1872 Amnesty Act on Representative Cawthorn’s qualification for access to the ballot, the attempt amounted to a judging of his qualifications for office. The district court had no jurisdiction to make that call.”

Praveen Fernandes, vice-president of the Constitutional Accountability Center, which filed an amicus brief, said: “Although Representative Cawthorn just lost his party’s nomination for his seat in Congress, today’s ruling remains an incredibly important one.

“It makes clear that the 1872 Amnesty Act poses no barrier to similar future … challenges of the qualification of candidates to appear on the ballot, thus ensuring that section three of the 14th amendment can continue to serve its purpose as an important mechanism for holding public officials accountable when they violate their oaths of office.”

Cawthorn did not immediately comment.