The far-right Republican Marjorie Taylor Greene appeared in court in Georgia on Friday for a hearing in an attempt to bar her from Congress for aiding the insurrection at the US Capitol on 6 January 2021.

A lawyer for Greene, James Bopp, tried to portray her as a “victim” of the Capitol attack, rather than an instigator.

Ron Fein, for the challengers, said: “The most powerful witness against Marjorie Taylor Greene’s candidacy … is Marjorie Taylor Greene herself.”

Greene, who testified, is set to appear on the Republican ballot for Georgia’s 24 May primary and has been endorsed by Donald Trump.

The administrative judge overseeing the hearing will present his findings to Georgia’s secretary of state, Brad Raffensperger, who will then determine whether Greene is qualified.

Raffensperger, a Republican, stood up to Trump when the then president tried to overturn Joe Biden’s 2020 victory in Georgia. Raffensperger has said that as a result, he feared for his family’s safety.

In a statement on Thursday, Trump incorrectly blamed Raffensperger and the Georgia governor, Brian Kemp, for allowing the challenge against Greene, saying she was “going through hell in their attempt to unseat her”.

The effort to bar Greene from re-election was brought by a coalition of voters and liberal groups and comes under the 14th amendment to the US constitution.

Passed after the civil war, the amendment was written to prevent anyone sitting in Congress if they have “engaged in insurrection or rebellion” or “given aid or comfort to the enemies” of the constitution.

On Friday, some in the room in Atlanta cheered and applauded as Greene took her seat – prompting the judge to later say such behaviour would not be tolerated. Matt Gaetz of Florida, another far-right Republican and Trump supporter, was in the room. He tweeted: “I’m here in Atlanta to support ⁦[Greene] against the assault on democracy that is this effort to remove her from the ballot.”

As the hearing began, Greene tweeted: “Only the People have the right to choose who they send to Congress.”

Supporters of Trump attacked Congress on 6 January 2021 in an attempt to stop certification of his defeat by Biden, in service of Trump’s lies about electoral fraud.

A bipartisan Senate committee connected seven deaths to the riot. More than 100 officers were hurt. About 800 people, including members of far-right and militia groups, have been charged, some with seditious conspiracy. Trump was impeached for inciting an insurrection but acquitted. A House investigation continues.

Organisers of events on January 6 have said Greene communicated with them. Greene has denied it and said she does not encourage violence. In October, however, she told a podcast hosted by Steve Bannon, Trump’s former chief strategist: “January 6 was just a riot at the Capitol and if you think about what our Declaration of Independence says, it says to overthrow tyrants.”

After the riot, Greene was one of 147 Republicans in Congress who objected to results in battleground states.

An effort to use the 14th amendment against Madison Cawthorn, a Trump ally from North Carolina, was unsuccessful, after a judge ruled an 1872 civil war amnesty law was not merely retroactive. In Greene’s case, a federal judge said the 1872 law did not apply.

In Atlanta on Friday, Bopp said the challengers were making a very serious charge.

“They want to deny the right to vote to the thousands of people living in the 14th district of Georgia by removing Greene from the ballot,” he said, adding that Greene “did not engage in the attack on the Capitol”.

Greene met Trump about objections to state results because of concerns about voter fraud, Bopp said. At the time of the riot, he said, she was at the Capitol urging people via social media to be safe and remain calm.

“Representative Greene was a victim of this attack,” Bopp said, adding that she believed her life could be in danger.

The challenge opened with questioning of a historian about the 14th amendment and uprisings including the Whiskey Rebellion of 1794, which was quashed by George Washington.

Ron Fein, a lawyer for the voters who filed the challenge, said Greene took an oath but broke it by engaging in an insurrection. Unlike past insurrections, Fein said: “The leaders of this insurrection were among us, on Facebook, on Twitter, on corners of social media that would make your stomach hurt.”

Although Greene was not on the steps of the Capitol, she played an important role in stoking Republican fury, Fein said. The day before the insurrection, Greene posted: “It’s our 1776 moment!” on the conservative-friendly Parler platform.

“The most powerful witness against Marjorie Taylor Greene’s candidacy … the most powerful witness in establishing that she crossed the line into engagement in insurrection is Marjorie Taylor Greene herself,” Fein said.

Bopp raised frequent objections. When Greene took the stand, the lawyer Andrew Celli became frustrated when she did not directly answer or said he was speculating.

Celli asked the court “to acknowledge that this is an adverse witness” and said: “Ms Greene, I’m just asking questions.”

“I’m just answering,” Greene said.

Celli asked Greene about posts on social media and other statements. Greene repeatedly said she did not recall them.

Whenever Celli suggested Greene endorsed the use of violence to interrupt the certification of the electoral votes, Greene said she did not support violence and was encouraging peaceful protest.

Celli played a clip of an interview the day before the riot in which Greene referred to “our 1776 moment”. Asked if she was aware some Trump supporters saw that as a call to violence, Greene said that was not her intention and she was talking about plans to object to electoral votes.

“I was talking about the courage to object,” she said.

The Associated Press contributed reporting