Paris, France (AFP) Social media was flooded with baseless claims of voter fraud in the final hours of the US presidential election — until Donald Trump claimed victory.

Key swing states Pennsylvania and Georgia were targeted with claims of ballot tampering and non-citizens voting, including videos US intelligence officials linked to Russia-backed disinformation campaigns.

Despite weeks of claiming that this year’s election was marred by widespread voting irregularities, the former president declared a victory “like no other” and pledged to “heal” the country in a stunning White House comeback.

Claiming fraud “has become a classic mobilization technique for populist or far-right leaders like Donald Trump”, said Julien Giry, a French expert in US disinformation.

Leaders will allege a loss was due to fraud, or claim “there was no fraud because we denounced it in advance”, he said.

Posts on X, the platform owned by Trump cheerleader and fellow billionaire Elon Musk, were instrumental in sowing doubt about the integrity of the voting process.

The so-called “Election Integrity Community” that Musk created to “share potential incidents of voter fraud or irregularities” spread multiple claims debunked by AFP, including that voting machines were flipping votes from Trump to Kamala Harris.

Other posts falsely shared images of ballot boxes being fraudulently discarded in hurricane-hit North Carolina.

But Trump’s decisive victory seems to have muted the online frenzy.

Hundreds of thousands of mentions of “fraud”, “voting fraud” and “cheating” peaked on social media the day of the election before falling sharply after Trump’s win, according to a network analysis tool from French company Visibrain.

“It is almost certainly quieter on this front today than it would have been had Trump lost or won narrowly,” said Ethan Porter, a professor and researcher at The George Washington University Misinformation/Disinformation Lab.

-‘A fine line’-

The former president never admitted defeat in the 2020 election, a denial that culminated with his supporters violently attacking the US Capitol weeks later in a bid to block certification of the vote.

Preying on an already tense political climate, disinformers also stoked fears of physical violence during this year’s presidential contest, culminating in false bomb threats at multiple polling places that authorities have attributed to a Russian interference campaign.

In the hours before polls closed, Trump claimed there was “a lot of talk about massive cheating” in Pennsylvania’s largest city and said law enforcement was “coming”.

A city official promptly denied the claim, calling it “yet another example of disinformation”, while Philadelphia police and the district attorney’s office rejected the unsubstantiated allegation.

Trump won the state’s 19 electoral college votes — considered the biggest battleground prize in this year’s vote — helping him reach the necessary minimum of 270 electoral votes.

Ahead of polls closing, online researcher Renee DiResta posted on social platform Threads that the influencers she was monitoring took a more subdued approach to fraud allegations on Election Day.

“There is a fine line between laying the groundwork to claim fraud if you lose, and not wanting to look foolish after if you complain loudly and your guy wins.”