Stewart Rhodes of the Oath Keepers poses during an interview session in Eureka
Oath Keepers militia founder Stewart Rhodes poses during an interview session in Eureka, Montana, U.S. June 20, 2016.

The trial of Stewart Rhodes, the founder of the far-right Oath Keepers militia, is set to begin next week in what could be the biggest test for the U.S. Justice Department in its quest to hold former President Donald Trump's supporters accountable for their Jan. 6, 2021, attack on the U.S. Capitol.

Rhodes and four other Oath Keepers associates are the first defendants in more than 10 years to face federal charges of seditious conspiracy under a Civil War-era statute that is rarely prosecuted in the United States and carries a statutory maximum sentence of 20 years in prison.The Oath Keepers is an anti-government militia whose membership includes current and former U.S. military and law enforcement personnel. Rhodes, a former Army paratrooper and Yale University-educated lawyer, founded the group in 2009.

The five on trial - Rhodes along with Kelly Meggs, Thomas Caldwell, Jessica Watkins and Kenneth Harrelson - are accused of plotting to use force to oppose the transfer of power from then-President Trump, a Republican, to his Democratic successor, Joe Biden.

Seditious conspiracy is defined as two or more people plotting "to overthrow, put down or to destroy by force the government of the United States."

Prosecutors have said the five defendants trained and planned for Jan. 6 and stockpiled weapons at a northern Virginia hotel outside the capital. As lawmakers met on Jan. 6 to certify Biden's election victory, some Oath Keepers stormed into the Capitol building, clad in paramilitary gear. They are not accused of carrying firearms onto Capitol grounds. Trump has made false claims that the election was "stolen" from him through widespread voting fraud.

Jury selection is due to begin on Sept. 27, and the trial is expected to last for several weeks.

The Justice Department's last attempt to prosecute a seditious conspiracy case was in 2010, when it charged members of a Michigan militia called the Hutaree. A judge acquitted them, ruling that the defendants' anti-government rhetoric was insufficient to prove they planned to act on their views.

"The Department of Justice has not had a great track record when it comes to seditious conspiracy cases," said Brandon Fox, a former federal prosecutor now with the law firm Jenner & Block.

To prove the charge, Fox said, prosecutors must show that the defendants not only spoke about using force against the government but that they also took steps to execute their plans.

Juries want to see "there is a realistic chance that this could have worked so they know it's not just puffery," Fox said, adding that he believes that in the Oath Keepers trial it could be harder for defense attorneys to argue that their clients were simply "blustering."

Prosecutors are expected to use video clips from the Jan. 6 attack, text messages and audio recordings of some of the Oath Keepers defendants. The digital evidence will be buttressed by testimony from about 11 FBI agents summarizing key details gleaned from tens of thousands of messages and hundreds of hours of video footage from the day of the attack.

THE BLIND SHEIKH

The last time the government won convictions in a seditious conspiracy case was in 1995, when a jury in Manhattan convicted Muslim cleric Omar Abdel-Rahman - known as the "Blind Sheikh" - and his co-conspirators in connection with the 1993 World Trade Center bombing and a broader plot to target other New York City landmarks.

What helped the government win that case, according to former lead prosecutor Andrew McCarthy, were the defendants' statements on waging war against America.

"There was no way that they could argue that somebody in the United States government put them up to it," McCarthy said, unlike in the Oath Keepers case in which militia members have said Trump summoned them to prevent the election from being "stolen."

"We've never had a sedition case where the defendants could credibly claim they thought the commander-in-chief of the United States was basically calling them into action because evil people in the government were trying to steal an election," McCarthy said.

A ruling made this month by U.S. District Judge Amit Mehta will restrict the Oath Keepers defendants from trying to lay any blame for their actions on Trump. Mehta barred them from using a "public authority" defense, meaning they cannot claim they relied on Trump's orders to break the law because he had no authority to call them to action on Jan. 6.

The judge is still deciding whether some of the defendants will be permitted to argue that there was no conspiracy because they were waiting for Trump to give them lawful authority to use force under the Insurrection Act, a law that empowers the president to deploy the military to suppress civil disorder.

Four other Oath Keepers members charged with seditious conspiracy are due to go on trial on Nov. 29. Several prominent leaders of the far-right Proud Boys group separately are due to go to trial on seditious conspiracy charges on Dec. 12.