Last February, some 20 men and their wives gathered for dinner at an upscale restaurant in Spokane, Washington, for their annual Valentine’s Day celebration. The men weren’t just friends; they did community service work together. They had been featured on local television, in khakis and baseball caps, delivering 1,200 pounds of food to an area veterans’ center; they were gearing up for their next food drive, which they called Operation Hunger Smash. A few days after the holiday, the men went camping in the snow-speckled mountains outside Spokane, where they grilled rib-eyes and bacon-wrapped asparagus over a bonfire.

They also engaged in more menacing activities. They assembled regularly — sometimes wearing night-vision goggles in the dark — to practice storming buildings together with semiautomatic rifles. Their drills included using sniper rifles to shoot targets from distances of half a mile. And they belonged to a shadowy organization whose members were debating, with ever more intensity, whether they should engage in mass-scale political violence.

They were among the thousands of members of American Patriots Three Percent, a militia that has long been one of the largest in the United States and has mostly managed to avoid scrutiny. Its ranks included cops and convicted criminals, active-duty U.S. soldiers and small-business owners, truck drivers and health care professionals. Like other militias, AP3 has a vague but militant right-wing ideology, a pronounced sense of grievance and a commitment to armed action. It has already sought to shape American life through vigilante operations: AP3 members have “rounded up” immigrants at the Texas border, assaulted Black Lives Matter protesters and attempted to crack down on people casting absentee ballots.

Now with the presidential election less than 100 days away, AP3 members see the fate of their country turning on a turbulent, charged campaign. They’re certain that Democrats will try to steal — not for the first time, in their view — the White House from Donald Trump. “The next election won’t be decided at a Ballot Box,” an AP3 leader wrote several months ago in a private Telegram chat. “It’ll be decided at the ammo box.” He has said he is ready to force his way into voting centers if need be, or “whatever it takes.”