WASHINGTON, May 26, 2023 (BSS/AFP) - Stewart Rhodes, founder of the far-right Oath Keepers militia, was dealt an 18 year prison sentence Thursday for seditious conspiracy in the 2021 attack on the US Capitol, the toughest penalty given yet over the January 6 assault.

"Seditious conspiracy is among the most serious crimes an American can commit," said Judge Amit Mehta in pronouncing the sentence.

"You present an ongoing threat and a peril to this country," Mehta told Rhodes, who led the Oath Keepers and organized their participation, with a stockpile of arms, in the attack on the Capitol by supporters of then-president Donald Trump.

"You are smart, charismatic and compelling and that is frankly what makes you dangerous," Mehta said -- rejecting Rhodes' claim that he was a "political prisoner."

The sentence fell short of the 25 years the government had sought, although Mehta accepted the argument that the Oath Keepers' plan to violently block Joe Biden from becoming president amounted to terrorism.

Just ahead of the sentence, Rhodes, wearing an eye patch and dressed in his orange prison jumpsuit, defiantly defended his group and their actions in support of Trump.

"I'm a political prisoner," he declared, comparing himself to the famed Soviet dissident Aleksandr Solzhenitsyn.

"My only crime is opposing those destroying our country," he said.