Shootings that left three dead at protests against police brutality have stoked fears of rising violence as a deeply divided US heads into elections amid economic collapse, a deadly pandemic and the worst social upheaval since the 1960s.
President Donald Trump, hoping to secure a second term in November despite the crisis, heads Tuesday to Kenosha, the Wisconsin town which descended into violence last week after police shot a young black father seven times in the back.
The governor of the state, Democrat Tony Evers, called on Trump in vain to reconsider his visit, warning it would "hinder our healing" and arguing that the citizens of the town are already traumatized.
One of them, Gregory Bennett, said he no longer feels safe in the town where last Tuesday night, a 17-year-old who had joined a far-right militia protecting private property shot dead two protesters.
Local white people "are in fear, they look for a reason to defend themselves and we have people over here [the militias] looking for a reason to attack," said Bennett, a social worker and former member of the military who said he no longer leaves his house without a bulletproof jacket and a pistol in his belt.
In the United States, where the right to defend oneself is part of the national identity, some 30 percent of the adult population owns at least one firearm.
Shots were also fired over the weekend in Portland, Oregon, where left-wing protesters have regularly faced off with police for the past three months.
As a group of Trump supporters clashed with the protestors, one of them, who was wearing a baseball cap with a local far-right group's logo, was shot dead on the fringes of the confrontation, in circumstances that are still unclear.
Between now and the election, "certainly there could be more shootings," said Spencer Sunshine, who researches far-right groups in the United States.
"It could get a lot worse because I don't think either side is going to back down," he warned.
Extremist groups have always existed in the United States, said Sunshine, an independent expert. After Trump's election, radical right-wing and left-wing groups regularly faced off in Seattle, Washington, as well as in Portland.
What is new, he said, is the widespread presence of firearms at demonstrations. "More than four years ago, you would only see an armed demonstration like in Arizona, where they have very liberal gun laws," he said.
Weapons have been particularly visible since May 1, when hundreds of men armed with assault rifles tried to enter the state capitol building in Michigan to protest against lockdown measures introduced to limit the spread of the coronavirus pandemic.
Sunshine said that show of force also illustrated the arrival of new recruits to the extreme right.
"It's no longer really white nationalists during the clashes, or white nationalists' collaborators," Sunshine said, indicating that right-wing populists, militias and conspiratorial Trump supporters were now also showing up, motivated by "social anxiety about what's going to happen to the country."
"The radical right is actively looking to exploit today's historically polarized political climate -- one that has become even more uncertain under the strain of the coronavirus pandemic and protests for racial justice," warned the Southern Poverty Law Center, which tracks extremist groups.
"With the 2020 presidential election fast approaching, the prospect that extremists might resort to political violence is a very real one," it said.
Up against the extreme right is a more diverse coalition of activists that Trump collectively calls "Antifa," short for "Anti-fascist," whom he accuses of being "rioters, anarchists, agitators and looters."
Its members "vary from thugs who like to fight... to those who are more truly defensive to those who are active on social media, trying to dox white supremacists," said Daniel Byman of the Brookings Institution.
He said they were less organized than their far-right adversaries but warned that "an increase in violence is quite possible, indeed likely."
Fueling the threat, Sunshine said, is a heady cocktail made up of "the zeal of the new convert added with lots of guns and hysterical narratives."