Proud Boys 'took aim' at US democracy

US prosecutors have accused leaders of the far-right Proud Boys group of plotting an assault on American democracy as one of the most high-profile trials to stem from the January 6, 2021 Capitol attack got underway.

In an opening argument, federal prosecutor Jason McCullough told jurors that Proud Boys chairman Henry "Enrique" Tarrio and four other leaders engaged in sedition by using force to try to keep Donald Trump in office after he lost the 2020 presidential election.

"On January 6, they took aim at the heart of our democracy," McCullough told jurors on Thursday.

Defendants' lawyers said it was Trump, not the Proud Boys, who spurred thousands of supporters to attack the Capitol.

"He's the one that told them to march over to the Capitol and fight like hell. Enrique didn't say that," said Sabino Jauregui, a lawyer for Tarrio.

The case marks the third time that the Justice Department has charged members of extremist groups with the rarely prosecuted crime of seditious conspiracy, after Trump supporters invaded the Capitol in a failed bid to prevent lawmakers from certifying his November 2020 election loss to Biden.

Oath Keepers founder Stewart Rhodes and another chapter leader of the far-right militant group were found guilty of seditious conspiracy in November, and another trial is pending against four more members.

The Civil War-era law, which prohibits people from plotting to overthrow or destroy the US government, carries a penalty of up to 20 years in prison.

When it became clear that Trump would not win re-election, "these men did not stand back. They did not stand by. Instead they mobilised," McCullough said, paraphrasing a comment Trump made in a debate before the election that the Proud Boys should "stand back and stand by".

All five Proud Boys defendants have pleaded not guilty and their lawyers will argue that they did not plot to block the peaceful transfer of power.

Prosecutors have brought criminal charges against more than 950 people following the assault. Four people died during the chaos, and five police officers died of various causes after the attack.

Under Special Counsel Jack Smith, the Justice Department is also investigating efforts by Trump's advisers to overturn his election defeat.