“BlueAnon,” a term inspired by the Right-wing conspiracy theory QAnon that refers to liberal conspiracy theories, went into a frenzy following the shooting.
Dmitri Mehlhorn, a political adviser to Reid Hoffman, a Democratic donor, urged supporters in an email late on Saturday to contemplate the “possibility… that this ‘shooting’ was encouraged and maybe even staged so Trump could get the photos and benefit from the backlash”.
He added: “Not one newspaper or opinion leader in America is willing to openly consider the possibility that Trump and Putin staged this on purpose. Ask the question, people.”
On Sunday, Mr Mehlhorn issued an apology and expressed regret over the email.
Some prominent anti-Trump accounts also suggested that the death of an audience member was part of the show.
“I can totally see Trump ‘sacrificing’ one of his cult followers to make his ‘assassination attempt’ look more realistic and believable,” wrote @LakotaMan1, the pro-Democrat influencer, who has more than 500,000 X followers.
The tweet was later deleted.
Misidentified shooter
The FBI named 20-year-old Thomas Matthew Crooks as the shooter on Sunday after he was shot dead by a Secret Service sniper, but conspiracy theories around the shooter spread widely before he was named.
Maxwell Yearick, an anti-Trump activist who served a prison sentence for clashing with police at a rally in 2016, was falsely labelled as the shooter by some accounts, even after Crooks was named.
Other accounts wrongfully claimed the shooting was the work of “Mark Violets”, a supposed member of the Left-wing “Antifa” movement. They spread his name along with pictures of Marco Violi, an Italian football journalist.
Mr Violi wrote on Instagram on Sunday: “I categorically deny that I am involved in this situation. He said he was woken up in the middle of the night by a flood of notifications, and that he would be reporting social media users who misidentified him as the shooter.