Where is James Talarico? The question ricocheted around rightwing echo chambers before metastasising into a conspiracy theory – and a reminder of the persistent danger of disinformation in the US midterm elections.

The smear campaign began when Talarico, the Democratic candidate for the US Senate in Texas, was not seen in public for nine days. His campaign was slow to explain why. While nature abhors a vacuum, Donald Trump and social media seize on one and weaponise it.

On 30 September, Talarico spoke at a Hispanic Business Council event by video. He had been diagnosed with the flu at an urgent care facility in Dallas after “starting to feel kind of under the weather a few days ago”, he said, and would not appear in person because he had a fever and was still contagious.

On 7 October, the president held a rally in San Antonio, Texas, and claimed without evidence that “Tala-freako”, as he nicknames the Democrat, is vegan. Trump asserted: “He’s sick because he’s been forced to eat meat for political reasons and he’s throwing up all over the place.”

On the same day, an X account with the username “Dan The Man, Always with a Plan” and a photo of “Trump 2028” cap tweeted without evidence: “He had a mental health crisis. That is what I heard from someone who would know inside information.”

On 8 October, Steve Bannon, a former White House chief strategist, stirred the pot further on his influential War Room podcast in an interview with former Trump fundraiser Caroline Wren, who baselessly claimed: “I’m hearing that he checked himself into a mental institution – that he had a full-blown, like, mental breakdown.”

On the same day, Ken Paxton, the Republican running against Talarico, weighed in with a social media post that showed Talarico on a “Wanted” poster and said: “Jimmy appears to be having a full-blown mental Tala-freak-out on the national stage. My campaign has a simple request: proof of life.”

On 9 October, Spencer Pratt, a former candidate for mayor of Los Angeles, offered his take: “My sources are telling me Talarico is in a mental health facility. His campaign has stopped actively planning events in the vital homestretch of the campaign.”

Right media sites swung into action. RedState, the Daily Wire, the Right Scoop, Twitchy and PJ Media all amplified the false claims. Elon Musk, the world’s richest man, put more toxins in the bloodstream with posts such as: “The Talarico campaign is hiding something big that voters ought to know about.”Then, on 11 October, came the supposed coup de grâce. Conservative social media influencer Nick Sortor posted a 47-second audio clip on X that he said proved that Talarico had been discharged earlier in the week from Lindner Center of Hope, a mental health treatment centre in Mason, Ohio.

The call was placed by Rhein Amacher, a self-described “right-wing provocateur”. In the clip, a woman whom Sorter claimed was an employee there says it looked like Talarico “was just discharged this evening”. The online Maga faithful were jubilant.

But not for long. The Bulwark obtained the full phone call showing the purported employee had repeatedly denied any record of Talarico being at the centre. The timeline also did not add up. Amacher said he made the call to the mental health centre on Saturday evening, but Talarico was seen at the Austin City Limits music festival on Friday. On Saturday, he made an appearance at a Kacey Musgraves concert in Dallas.

The Lindner Center of Hope wrote in an X post on Sunday that Talarico “has never received treatment” from the facility. Talarico replied to the post, saying, “I’ve never even been to Ohio.”He included a tears of joy emoji.

JT Ennis, a spokesperson for Talarico, called Sorter’s claim “a lie designed to promote a pathetic conspiracy theory” in an X post and wrote that Talarico had been recovering from the flu at his home in Austin. Talarico has type 1 diabetes, placing him at higher risk for flu-related complications.

Even Maga followers began to acknowledge that the claim had collapsed. But if the episode appeared absurd, its implications for the midterms were serious.

Reed Galen, a former Republican strategist and cofounder of the Lincoln Project, an anti-Trump group, said: “It was a bit wild but a good reminder to all of us how sophisticated, effective and efficient the rightwing/ bot/ Russian generated misinformation-disinformation machine is.

“This story came from some weirdos in Ohio or whatever but the point is that someone or something picked it up and amplified it to a point where – despite no evidence of reality – it became something that was an issue in the Texas Senate campaign.”

Its list of false claims includes Abdul El-Sayed, the Democratic candidate for US Senate in Michigan, having called for sharia law in the US during a 2022 speech; a Dominion Voting Systems whistleblower accusing US politicians of taking millions of dollars in bribes to rig the 2026 midterm elections; and Ken Paxton’s Senate campaign paying for a Texas billboard that says “Pedos Ain’t That Bad”.

Another example related to an image that purportedly showed Rob Sand, a centrist Democratic candidate for governor of Iowa, campaigning with the progressives Ilhan Omar and Tim Walz. NewsGuard found it was generated by artificial intelligence (AI).

Even as AI gives new tools to nefarious actors, defences have been weakened. Last year, US secretary Marco Rubio shut down the state department’s Counter Foreign Information Manipulation and Interference office, accusing it of censorship and wasting US taxpayer money.

Major tech platforms – notably Musk’s X and Mark Zuckerberg’s Meta – have gutted trust, safety and factchecking teams, turning online spaces into a lawless wild west. Musk has spent a record $366m in the election cycle so far to help Republicans retain control of Congress.

Richard Hasen, a professor at UCLA School of Law and election law expert, said: “When you’ve got Elon Musk owning one of the important social media platforms and being a vector for spreading the misinformation, and also when you’ve got the companies like Meta no longer doing the same kind of trust and safety work, it’s just an atmosphere where this kind of stuff can spread.”But there is another, more optimistic perspective. While the Talarico rumours spread like wildfire in corners of the internet, they did not penetrate the mainstream media, and fizzled out once the reality became clear.

Hasen added: “The Talarico case shows the limits of being able to do this. This was something that was easily disproven and could have potentially even backfired, showing that the anti-Talarico forces are so desperate that they have to make up a false claim to try to boost a weak candidate.

“Every election now we’re hearing it’s going to be ‘the AI election’ and voters are going to be tricked. What I think is happening in part is that everyone’s on their guard. We all know that we can’t necessarily believe our eyes or our ears and things that a politician might appear to say or do might not necessarily be true, so that’s a little bit of a natural check.”

Hasen points out that candidates are better equipped to dismantle digital lies. To debunk the rumour, Talarico shared home security camera footage with the New York Times, establishing his presence at home. “Because we’re leaving digital footprints everywhere, that sometimes could be another way to debunk a rumour.”Tara Setmayer, a former Republican communications director on Capitol Hill, also believes that the conspiracy theories have lost their novelty value. “The voters have become hip to this game,” she said. “There are too many other negative things going on in everyday American lives, so I don’t think these types of cheap attacks are going to resonate at this point.

“The difference between this election cycle and past election cycles is that, because it seems like we’ve been here before and we know how batshit crazy Maga can be, that mainstream media isn’t platforming the crazy as often,” said Setmayer. “They’re actually reporting it in a way with the healthy amount of scepticism that it deserves, so it’s dismissed off the top whereas in the past it was so novel.”

Setmayer added: “At this point now it feels like Donald Trump and Maga’s greatest hits: we’re really in the fat Elvis period of the Maga election campaign tactics and it’s obvious to everyone. The absurdity is finally breaking through even with some Republican voters, evidenced by how terrible Donald Trump’s numbers are and Republicans writ large.”