The cellphone video shot in the dark by a woman in a parked car appeared to show something ominous: a man closing the doors of a white van and then rolling a wagon with a large box into a Detroit election center.

Within hours, the 90-second clip was being shared on news sites and conservative YouTube accounts, offered as apparent proof that illegal votes were being smuggled in after polls closed. Prominent Republicans, including Eric Trump, one of the president’s sons, amplified the falsehoods on social media. Within a day, views of the video shot up past a million.

That single video serves as a powerful emblem of the trafficking in false information that has plagued the presidential election won by Joe Biden. In other videos, photos, and social media posts, supporters of President Donald Trump, and most notably the incumbent himself, have raised doubts about the outcome based on problems that did not occur.

Though the clip was quickly discredited by news organizations and public officials — the man depicted was a photojournalist hauling camera equipment, not illegal votes — to many viewers it had its intended effect.

Eric Hainline, a UPS driver from Dayton, Ohio, said that video and others he watched like it reinforced his suspicions that the election was stolen from Trump.

“You don’t know who to believe anymore,” said Hainline, 44. “I think the trust people have is broken.”

Trump and his allies have fomented the idea of a “rigged election” for months, promoting falsehoods through various media and even lawsuits about fraudulent votes and dead voters casting ballots.

While the details of these spurious allegations may fade over time, the scar it leaves on American democracy could take years to heal.

“There will always be people who believe the Democrats stole the election in 2020,” said Jennifer Mercieca, a historian of political rhetoric at Texas A&M University. “That will not change.”

In fact, there is no evidence of widespread fraud in the 2020 election. Election officials confirmed there were no serious irregularities and the election went well. Attorney General William Barr said Tuesday the Justice Department has not identified voter fraud that would change the presidential election.

But from the Oval Office, Trump has consistently tried to mislead the nation about the outcome. As a result, cries of voter fraud have persisted loudly in an online media ecosystem where pro-Trump Facebook pages, Twitter accounts and fringe websites readily circulate unchecked or misleading claims about the voting process.

And one of those falsehoods sprang from the cellphone camera of Kelly SoRelle, a Republican from Texas. After shooting her video of the man with a wagon in Detroit, SoRelle took it to a conservative YouTube host who played it for his show’s 5 million subscribers the day after the election. She also gave it to the Texas Scorecard, a website started by Empower Texans, a lobbying group whose PAC has pumped millions of dollars into the campaigns of ultra-conservative candidates. SoRelle did not respond to requests for comment.

Over the next week, there were nearly 150,000 mentions of wagons, suitcases or coolers of votes in broadcast scripts, blogs and on public Facebook, Twitter or Instagram accounts, according to an analysis that media intelligence firm Zignal Labs conducted for the AP. Mentions of the story began to fizzle out on Nov. 5, after news organizations fact-checked the claims, Zignal Labs' report found.

By then, however, many of those fringe websites and Trump associates were busy peddling new claims of voter fraud online.

Some claimed 100,000 ballots were “magically found” in Milwaukee at 3 a.m. when, in reality, the city’s election director, escorted by police, had just delivered thumb drives of data with the count of roughly 169,000 absentee ballots to the county courthouse so the results could be uploaded. Others suggested that Dominion Voting Systems, one of the country’s most widely used voting technology firms deleted or switched votes — an impossible feat that never happened, the company says, a finding confirmed by the federal agency that oversees election security.

Meanwhile, in lawsuits, tweets and Facebook posts, the Trump campaign started naming voters in Georgia, Nevada and Michigan they believed were dead. Among them was Mrs. James E. Blalock, a Georgia widow who registered to vote using her married name and is alive.

In Georgia, where Biden won, other false claims that computers deleted Trump votes or ballots were tossed into the garbage have littered social media feeds. Fellow Republicans, including the president, accused Georgia’s GOP secretary of state, Brad Raffensperger, of being a “liar” who failed to root out “illegal” votes in the state.

“There are those who are exploiting the emotions of many Trump supporters with fantastic claims, half-truths, misinformation and, frankly, they’re misleading the president as well, apparently,” Raffensperger said Monday.

The social media platforms have tried to slow the reach of some of those falsehoods. Twitter and Facebook have also fact-checked false claims on their sites. Since Election Day, Twitter has flagged more than 100 of the president’s tweets about the vote, some of which it prohibited users from sharing, commenting on or liking. Facebook has labeled the president’s misleading posts but not limited users’ ability to spread the falsehoods across its platform. On Wednesday, Trump used Twitter and Facebook to deliver a 46-minute diatribe of misstatements about the election to his collective following of 100 million users on the two platforms.

A sizable majority of Trump backers still believes the election was stolen. A survey last month by Monmouth University found that almost one-third of Americans, and more than 75% of Trump supporters, believe Biden only won because of fraud.

Myra C. Ruiz, 77, is one of those Trump supporters who believes the president was cheated.

“I heard two days ago that Trump said he didn’t lose this election; it was taken from him,” said Ruiz, who lives in New Orleans.