Kicked off Twitter and Facebook after his supporters stormed the US Capitol, Donald Trump eventually set up his own platform Truth Social, declaring in April 2022 after a stumbling launch: "I'm Back! #COVFEFE."
Yet to concede his loss to Joe Biden, Trump is now signaling he will seek the White House again in 2024.
And with midterm elections Tuesday, he is doubling down on voting conspiracy theories he has wielded ever since the 2016 election, which he won, and amplified since his defeat four years later.
In the past 58 days, Trump has shared about 100 posts on Truth Social casting doubt on the integrity of US elections, according to an AFP analysis of the former president's more than 1,200 interactions in that period.
"Here we go again!" Trump wrote November 1, sharing a misleading headline about ballots in Pennsylvania, a swing state he lost to Biden but which next week could determine if Republicans win back the Senate.
The tactics mirror his 2020 playbook, when he tweeted repeatedly before the election that mail-in ballots were rife with fraud. Dozens of court cases have since ruled otherwise.
But such misinformation could undermine confidence as Americans vote in the first national polls since the January 6, 2021 insurrection at the Capitol, experts say.
"If leaders tell their followers that elections are unreliable, their followers believe them," Russell Muirhead, professor of politics and democracy at Dartmouth College, told AFP.
"Trump's insistence that elections are flawed (when they're not) is doing one thing: it is corroding American democracy."
Trump posts often on Truth Social, sometimes dozens of times a day.
In the last two months, he has attacked Biden and Democrats, criticised ongoing investigations against him and glorified his own rallies and accomplishments.
Trump has also lavished praise on Republicans who support his stolen-election claims, such as Kari Lake, who has signaled she may reject the results if she loses her bid to become Arizona governor.
And he has engaged more brazenly than ever with extremist content, including dozens of posts from promoters of the QAnon conspiracy theory.
Although Trump's reach on Truth Social is relatively small -- 4.46 million compared to the 88.8 million he enjoyed on Twitter -- experts say the misinformation he spreads reverberates across the internet.
"After Trump puts the toxin in the water, the whole lake is spoiled," said Muirhead, who was elected to the New Hampshire House of Representatives as a Democrat in 2020 after writing a book about conspiracism entitled "A Lot Of People Are Saying" -- a play on a Trump catchphrase.
Trump's office and main political action committee, Save America, did not respond to requests for comment.
The former president has boosted hundreds of pro-Trump articles, polls and memes -- including some that reference QAnon and come from accounts with names such as "Patriotic American Alpha Sauce." One post he shared called Biden "#PedoHitler."
"Trump still has an outsized impact on the Republican Party and on the right-wing media ecosystem more broadly, and every claim he makes gets amplified," said Rebekah Tromble, director of George Washington University's Institute for Data, Democracy, and Politics.
In October, Trump promoted several posts from Melody Jennings, founder of a group that organized stakeouts of ballot drop boxes in Arizona to catch suspected fraud.
The posts included Jennings' claim of "mules" at a box near Phoenix -- a reference to a discredited film's conspiracy theory about people smuggling illegal votes -- and a picture of a voter.
The voter in question was depositing ballots for himself and his wife, who was in the car, according to a witness statement he provided in a lawsuit against Jennings' group, Clean Elections USA. He also filed a state voter intimidation complaint.
The incident is reminiscent of Trump's false 2020 claims that Georgia election workers were caught counting "suitcases" of fraudulent ballots in the dead of night. The video Trump retweeted showed normal processing of legal votes, state officials concluded.
Election workers Ruby Freeman and her daughter Shaye Moss received death threats. At the FBI's urging, Freeman left her home for two months.
Twitter's new owner Elon Musk has indicated he plans to lift the ban on Trump -- though not before the midterms.
If Trump announces another presidential bid, both Twitter and Facebook may feel pressure to give back the megaphone to the once-prolific ex-president.
"This is not a game," said Ben Berwick, counsel at Protect Democracy, a non-profit group that backed the lawsuit against Clean Elections USA. "Debunked conspiracy theories like those about so-called ballot mules cause real harm to innocent Americans."
