The atrium of Cinemark Fairfax Corner could not be described as characterful. The yellow walls, arcade games and rows of snacks and popcorn might be any bland multiplex cinema anywhere. But the digital dashboard of films currently playing merits a second glance.

Along with Bad Guys, Doctor Strange in the Multiverse of Madness and Everything Everywhere All at Once, there is the title 2000 Mules. Anyone hoping for a superhero blockbuster about an army of horse-donkey hybrids will be disappointed.

Instead, Donald Trump’s “big lie” has arrived at a cinema near you.

2000 Mules claims to be an investigation of voter fraud in the 2020 presidential election. It purports to show that Democratic-aligned ballot “mules“ were paid to illegally collect and drop off ballots in Arizona, Georgia, Michigan, Pennsylvania and Wisconsin, tipping swing states in favour of Joe Biden against Trump.

The “documentary” has been resoundingly debunked by factcheckers who point out that its supposed smoking gun – $2m worth of anonymised mobile phone geolocation data that allegedly tracks the “mules” visiting drop boxes – is based on false assumptions about the accuracy of such technology.

But that has not prevented 2000 Mules earning praise from Trump and other Republicans, gaining a limited cinema release and becoming something of a sacred text in the discredited “Stop the steal” conspiracy theory narrative.

So it was that on a quiet Wednesday afternoon, a dozen people – most of them white and middle-aged or elderly – took their seats at Cinemark Fairfax Corner for a screening. Unusually and perhaps tellingly as the lights went down, there were no trailers for other movies.

The main feature turned out to be more restrained than critics of the big lie might expect. Far-right film-maker and provocateur Dinesh D’Souza seeks to present himself as curious, innocent and reasonable – just asking questions – as he interviews commentators and “experts” about the conduct of the 2020 election.

In fact, D’Souza is so determined to avoid the raucous tone of Trump’s rallies or Fox News’s opinion hosts that at times the 88-minute film is, surprisingly, just plain dull. But by the end he does emphatically conclude that the election was rigged and stolen by Democrats as an ominous, plaintive version of The Star-Spangled Banner swells.

Among this group of cinemagoers, at least, D’Souza was preaching to the converted. All had gone in convinced that Biden is not legitimately elected president. The film, like a social media echo chamber, delivered a satisfying dose of confirmation bias.

“I thought it was spectacular,” said Joe Hughes, 67, who is self-employed. “Trump never stood a chance in that election.”

Joyce Gould, 69, an accounting administrator, agreed: “When Trump talked about stuff that was going to happen, I didn’t have any reason to doubt him. I figured there was a lot of cheating going on. But when you actually see the details in the film as far as the geo-technology and all that kind of stuff? Sure.

“I’m just surprised at the evil that is out there in the world. You always know it’s there, but when you actually hear the details of it, it’s just very astounding to me.”

A man who gave his name only as Bill, and his age as above 50, described the film as “nauseating and extremely compelling if you have an open mind”. He insisted: “I’m a very objective person. If my own children were charged with a crime, I’d be on the jury. That’s how objective I am.”

But he added: “My frustration is with Trump. He knew it was going to happen. He did nothing to stop it. That’s also very nauseating to me.”

Will this film actually change minds? Bill’s wife, Anna, 63, who works for an airline, commented: “It might wake up some people that aren’t woken but I don’t know who will come to watch it. I doubt some with a certain political affiliation are willing to because they don’t want to see it or hear it.”

2000 Mules was produced by D’Souza and uses research from the Texas-based non-profit True the Vote, which has spent months lobbying states to use its findings to change voting laws.

A special screening at Trump’s luxury Mar-a-Lago estate in Palm Beach, Florida, was attended by prominent supporters of his assault on democracy: Congresswoman Marjorie Taylor Greene of Georgia, Trump lawyer Rudy Giuliani and MyPillow entrepreneur Mike Lindell.

Clips from the film have regularly featured at Trump’s campaign rallies and it was shown in full before he took the stage in Greensburg, Pennsylvania. The former president has praised 2000 Mules for exposing “great election fraud”.

There are signs that it could become a cultural touchstone for Republicans, granting a patina of gravitas and respectability to the big lie that does not come from rumors, speeches or internet chatrooms.

Ronny Jackson, the White House’s former top physician who is now a member of Congress, tweeted: “If you don’t think there was MASSIVE voter fraud in the 2020 election after seeing 2000 Mules, then NOTHING can convince you. The amount of criminal fraud all caught ON CAMERA will SHOCK you! 2020 was NOT “free & fair” at ALL. GO SEE 2000 MULES!!”

Kandiss Taylor, who ran for governor of Georgia in this week’s Republican primary election, bemoaned the lack of investigations into voter fraud: “There’s been none in Georgia outside 2000 Mules that just came out, outside of data teams all over the state that are private citizens.”

However, factcheckers have eviscerated the movie, noting its flawed analysis of mobile phone location data, which is not precise enough to confirm that someone deposited a ballot into a drop box as opposed to merely walking or driving nearby.

Aaron Striegel, a professor of computer science and engineering at the University of Notre Dame, told the Associated Press: “You could use cellular evidence to say this person was in that area, but to say they were at the ballot box, you’re stretching it a lot. There’s always a pretty healthy amount of uncertainty that comes with this.”

2000 Mules also contains drop-box surveillance footage that showed voters depositing multiple ballots into the boxes. But it is impossible to tell whether those voters were the same people as the ones whose mobile phones were anonymously tracked.

Critics also point out that D’Souza has form. He has spent years promoting disinformation. In 2007 he wrote that “the cultural left is responsible for causing 9/11”. In 2014 he was convicted of violating federal election law by making illegal donations to a US Senate campaign only to be pardoned by Trump in 2018.

Yet 2000 Mules has been released in more than 270 cinemas across the US with most distribution provided by Cinemark, the third biggest chain in the country. The Popular Information website pointed out that Cinemark’s founder and board chairman, Lee Roy Mitchell, “is a major financial backer of Trump and rightwing misinformation platforms”.

Given Trump’s obsession with ratings, it would not be a huge surprise if he now claims to have rescued the American box office. But the release of 2000 Mules is very modest compared to the typical Hollywood blockbuster.

Dan Cassino, a government and politics professor at Fairleigh Dickinson University, in Madison, New Jersey, said: “It’s not a widespread release. This is not Doctor Strange. This exists because there is a market for it.

“It’s hard to believe that this sort of very blatant propaganda that doesn’t address the question it’s supposed to is going to convince anyone who didn’t already believe that this was real. This is a way of giving additional talking points to people who already believe that the election was stolen.”

Purveyors of Trump’s false election claims took a hammering in this week’s Republican primary elections in Georgia. But some watchdogs warn that, about 18 months after the presidential election, the mere existence of 2000 Mules could yet breathe new life into the big lie.

Gunner Ramer, political director of the Republican Accountability Project, said: “We get angry emails in our inbox all the time - we’re dumb, terrible RINOs [Republicans In Name Only] or whatever - and one thing I have noticed is that people do mention 2000 Mules.

“Among the still-can’t-get-over-the-2020-election-loss crowd, they are watching this. It has made an impact with them and reinforced the big lie.”