Federal prosecutors had asked for a nine-year sentence for Mr. Garbin. Mr. Garbin and most of the men in the Michigan case were inspired by the so-called boogaloo movement, the authorities say.
Boogaloo followers — the name is drawn from a cult film — believe that the United States is on the brink of a civil war that devotees seek to accelerate.
“Such accelerationist groups are widespread and proliferating,” federal prosecutors wrote in their sentencing memorandum, using the Capitol riot on Jan. 6 as an example of the potential for chaos.
A strong sentence would discourage imitators, the prosecutors wrote, while “an insufficient sentence will encourage such groups to plot and prepare.”
Several people associated with the loosely affiliated boogaloo movement have been arrested around the country on charges linked to different plots.
In California, Steven Carrillo, an active-duty Air Force sergeant, pleaded not guilty and awaits trial in the shooting death of a federal security officer outside a courthouse in Oakland in May 2020 as well as the killing of a sheriff’s deputy in Santa Cruz County a few days later.
During the shootout that led to his arrest, Sergeant Carrillo used his own blood to scrawl “Boog” and other phrases linked to the movement on the hood of a car he had stolen. On Monday, one of four members of the anti-government Grizzly Scouts paramilitary group linked to Mr. Carrillo pleaded guilty in federal court in California to destroying evidence in the case.
In Las Vegas, three boogaloo followers who were arrested in May 2020 are expected to go on trial in January. They are accused of trying to incite violence after plotting to throw firebombs during a Black Lives Matter protest. They also face state terrorism charges.