ADELANTO, Calif. — Though it was billed as a grass-roots, nonpartisan event intended to oppose government Covid-19 mandates, a trucker demonstration that left California for Washington, D.C., on Wednesday appeared to be tightly aligned with far-right organizations and activists.
Many of those behind the demonstration, which was planned as an American version of the past month’s chaotic Canadian protest, have connections to the violent attack on the Capitol in January 2021, or supported the lie that fraud in the 2020 presidential election was to blame for Donald J. Trump’s loss.
“We’re just trying to show what the people who back us believe — and our own beliefs — of what our country needs to go back to,” said Jeff Sandberg, a Republican truck driver from Texas whose vehicle was hauling a massive banner covered in slogans such as “We Will Not Comply!!” and “Let’s Go Brandon,” a meme created to insult President Biden.
Brian Brase, a convoy spokesman and Ohio-based truck driver, said the motorcade was expected to grow as the trucks wended across the country. “We believe tens of thousands will join in,” he said.
About 40 truckers were on hand with their rigs as the convoy rolled out on Wednesday in Adelanto, Calif., about 180 miles west of the Arizona state line. A flag-strewn send-off rally that resembled a Make America Great Again event drew about a hundred more vehicles.
At truck stops in the surrounding area, most local drivers seemed only dimly aware of the California convoy or too busy to take part. Unlike in Ottawa, where a recent weekslong protest shut down parts of Canada’s capital, the activity near Barstow, Calif., on Wednesday seemed highly staged, with memorabilia stands and food trucks.
The group behind the convoy — one of several in the United States expected to launch over the next few days — is demanding an end to the national emergency, meant to streamline the government response to the pandemic, that was first declared by Mr. Trump in March 2020 and recently extended by Mr. Biden. The protesters also want congressional hearings into the origin of the pandemic and an end to government health rules requiring masks and vaccinations, a move that has already begun as new cases have ebbed.
Law enforcement authorities warned against disruption of the sort that roiled Canada for several weeks.
“Attempting to block or shut down a freeway or state highway to protest is unlawful, dangerous and prevents motorists from safely reaching their destinations,” the California Highway Patrol said in a statement. “If necessary, the C.H.P. will take enforcement action that includes, but is not limited to, issuing citations, impounding vehicles, arresting individuals who intentionally block traffic on the state’s transportation system or pose a threat to public safety.”
In Washington, officials from the U.S. Capitol Police said they would facilitate the demonstration as a “lawful First Amendment activity,” but also had set some security measures in motion. The Defense Department authorized deployment of about 700 unarmed National Guard personnel from the District of Columbia and neighboring states to help manage traffic, and Capitol Police said that plans were being drawn up to reinstall the temporary fence that was erected around the Capitol after last year’s Jan. 6 riot.
An American trucker protest has been discussed for at least a month on social media and right-wing news outlets, inspired by the one that crossed Canada, demanding an end to a mandate requiring truckers crossing the U.S.-Canada border to get vaccinated against Covid-19.
American truckers have no such mandate, and as a towering surge in new cases has rapidly ebbed, most states — including California — have eased restrictions. But Mr. Brase said his group felt compelled to express solidarity with health care workers, public employees and others for whom vaccination has become a requirement.
Last week, a conservative political action committee that has focused in the past on defending Representative Matt Gaetz, a Florida Republican and ally of Mr. Trump who is being investigated by the Justice Department, issued a call for participation in an American convoy that would start in Ohio and California and reach Washington on March 6.
Darrel Courtney, the chief executive of the Adelanto Stadium and Event Center, said he received a call last Tuesday from Leigh Dundas, an Orange County lawyer and Republican activist, who wanted to rent the parking lot. Ms. Dundas, a lawyer for an anti-vaccine group whose leader was charged with entering the U.S. Capitol on Jan. 6, was videotaped the day before the riot rallying pro-Trump crowds with calls to kill any “alleged Americans” who might have helped undermine the 2020 elections.
Two hours northeast of Los Angeles, Adelanto is known chiefly for its prisons. Gabriel Reyes, the city’s part-time mayor — a Republican who operates a small currency trading and marketing business — said the city-owned stadium, which once hosted minor league baseball, was little used except for an annual cannabis festival, “Kushstock.”
“I didn’t see us making beaucoup bucks off of this,” he said, “but if they all want to fill up at our Arco station and we get that California tax, then hey, we’re going to say, ‘Thank you!’”
On Wednesday, the mayor’s wife sang the national anthem for the truckers before they departed for their next stop, Kingman, Ariz. Speakers at the rally included Dr. Pierre Kory, a vocal advocate of the discouraged use of the anti-parasitic drug ivermectin as a Covid-19 treatment, and Rob McCoy, a Republican politician and Southern California evangelical pastor who has gained prominence flouting pandemic rules and calling the state’s governor, Gavin Newsom, “Governor Newssolini.”
Ms. Dundas, who was the event’s M.C., said, “It’s been two years, and it is time to open this darn economy with no more restrictions on it.”
A list of organizations supporting the convoy included those led by Robert F. Kennedy Jr., a leader in the anti-vaccine movement, and Gen. Michael Flynn, the former Trump administration national security adviser.
That latter group, the America Project, has combined its attempts to challenge Covid-19 policies with the relentless promotion of pro-Trump election conspiracy theories. The group is run by Patrick Byrne, the former chief executive of Overstock.com, who, with General Flynn, was central in a bizarre plot to persuade the former president to use the military to seize voting machines in a bid to stay in power.
Yet another group, the American Foundation for Civil Liberties and Freedom, which is raising money for the truckers, hosted an event in Los Angeles last summer at which participants promoted baseless claims that there were widespread irregularities in the presidential voting results in Michigan.
Outside Adelanto, Mario Acevedo, who had stopped to wash the tires of his big rig on the way to Nevada, said he did not “have that time or luxury, unfortunately,” to skip work for the convoy.
“I got to provide for my family,” he said.
Shawn Hubler reported from Adelanto, Calif., and Alan Feuer from Albany, N.Y. Eric Schmitt contributed reporting from Washington.
