Voter intimidation is defined by the Institute for Constitutional Advocacy and Protection, part of Georgetown Law, as, among other things, “brandishing firearms or the intimidating display of firearms".
Stewart Rhodes, Oath Keepers’ leader, told the Los Angeles Times on Saturday that his group would “be out on Election Day to protect people who are voting”.
He said that some members would be carrying concealed weapons.
Rhodes said that he was worried about "the radical left" targeting voters and preventing them from casting their vote.
Trump supporters are more likely than Biden supporters to vote in person, according to a Pew Research survey from the end of July.
"I'll be voting in person and so will everybody else I know, and I think the radical left knows that," Rhodes said.
He said that his group would report issues to the police initially but that he's "not confident police will do their job."
He said if his group noticed, for example, protesters at polling sites with guns, "we're going to intervene."
"We've done it before," he said. "If the cops are doing their job, we'll just stand by. If they're not, we'll step in."
Other groups have discussed online their plans for 3 November.
One group affiliated with QAnon - the baseless conspiracy theory claiming Trump has been sent to save the US from a cabal of Satanist pedophiles operating as “the deep state” - was found by the SITE Intelligence Group to be preparing to deploy.
They said that "heavily armed MAGA patriots" were preparing for election day.
Heidi Beirich, Georgia-based co-founder of the Global Project Against Hate and Extremism, said they feared violence was most likely in cities which have been targeted by Mr Trump - among them Portland, Oregon; Seattle; Louisville; Kenosha, and Detroit.
Laws differ by state when it comes to whether you can bring a weapon to a polling site — concealed, unconcealed, or at all.
Openly carrying a firearm at a polling station could be interpreted as voter intimidation which is illegal in the US.
And all 50 states prohibit private, unauthorised militias and military units from engaging in activities reserved forthe state militia, including law enforcement activities.
Cassie Miller, a senior researcher with the Southern Poverty Law Center, told the Times that "chances are really high that we're going to see militia members, armed groups, or Trump supporters who are armed at the polls."
She said: "Not only are these people willing to participate in voter intimidation, but they're hoping to create this chaotic moment.
"There's an unwillingness to accept anything but a Trump victory."
At a rally last month in Portland, the Proud Boys announced plans to monitor Oregon sites where mailed ballots were dropped off, Ms Miller noted.
Devin Burghart, the executive director of the Institute for Research and Education on Human Rights, told the Times that his organisation believed far-right groups would be standing by at polls in Michigan, Pennsylvania, and Wisconsin and that "the act of showing up armed is certainly a deterrent to folks showing up to vote".
Burghart said people could report such groups via his group's app, which is designed to alert local legal observers.
In some areas, the voter intimidation has already begun.
Two right-wing agitators, Jack Burkman and Jacob Wohl, were arrested on 8 October in connection with voter intimidation charges, and face up to seven years in prison.
Richard Cunningham, the Michigan assistant attorney general, accused Burkman and Wohl of being behind a "racially insensitive robocall" that falsely claimed to callers if they vote by mail they will be placed in a database that will be used to track down people with outstanding warrants, used by creditors to collect debts, and by US Centers for Disease Control and Prevention to make people get vaccinated.
They are believed to have made 85,000 robocalls to people in areas, like Detroit, which have a high percentage of voters from communities of colour.