The witch craze could not have traveled as far or lasted as long without the printing press. Malleus Maleficarum (Hammer of the Witches), a 1486 screed by the German witch-hunter Heinrich Kramer, became the best-selling witch-hunter’s handbook, going through 28 editions by 1600. Similarly, it was the books and pamphlets “exposing” the Illuminati that allowed those ideas to spread everywhere following the French Revolution. And in the early 20th century, the introduction of the radio facilitated fascist propaganda. During the 1930s, the Nazi-sympathizing Catholic priest and radio host Charles Coughlin broadcast his antisemitic conspiracy theories to tens of millions of Americans on dozens of stations.
The internet has, of course, vastly accelerated and magnified the spread of conspiracy theories. It is hard to recall now, but in the early days it was sweetly assumed that the internet would improve the world by democratizing access to information. While this initial idealism survives in doughty enclaves such as Wikipedia, most of us vastly underestimated the human appetite for false information that confirms the consumer’s biases.
Politicians, too, were slow to recognize the corrosive power of free-flowing conspiracy theories. For a long time, the more fantastical assertions of McCarthy and the Birchers were kept at arm’s length from the political mainstream, but that distance began to diminish rapidly during the 1990s, as right-wing activists built a cottage industry of outrageous claims about Bill and Hillary Clinton to advance the idea that they were not just corrupt or dishonest but actively evil and even satanic. This became an article of faith in the information ecosystem of internet message boards and talk radio, which expanded over time to include Fox News, blogs, and social media. So when Democrats nominated Hillary Clinton in 2016, a significant portion of the American public saw a monster at the heart of an organized crime ring whose activities included human trafficking and murder.
Nobody could make the same mistake about misinformation today. One could hardly design a more fertile breeding ground for conspiracy theories than social media. The algorithms of YouTube, Facebook, TikTok, and X, which operate on the principle that rage is engaging, have turned into radicalization machines. When these platforms took off during the second half of the 2010s, they offered a seamless system in which people were able to come across exciting new information, share it, connect it to other strands of misinformation, and weave them into self-contained, self-affirming communities, all without leaving the house.
It’s not hard to see how the problem will continue to grow as AI burrows ever deeper into our everyday lives. Elon Musk has tinkered with the AI chatbot Grok to produce information that conforms to his personal beliefs rather than to actual facts. This outcome does not even have to be intentional. Chatbots have been shown to validate and intensify some users’ beliefs, even if they’re rooted in paranoia or hubris. If you believe that you’re the hero in an epic battle between good and evil, then your chatbot is inclined to agree with you.
It’s all this digital noise that has brought about the virtual collapse of the event conspiracy theory. The industry produced by the JFK assassination may have been pseudo-scholarship, but at least researchers went through the motions of scrutinizing documents, gathering evidence, and putting forward a somewhat consistent hypothesis. However misguided the conclusions, that kind of conspiracy theory required hard work and commitment.
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Today’s online conspiracy theorists, by contrast, are shamelessly sloppy. Events such as the attack on Paul Pelosi, husband of former US House Speaker Nancy Pelosi, in October 2022, or the murders of Minnesota House speaker Melissa Hortman and her husband Mark in June 2025, or even more recently the killing of Charlie Kirk, have inspired theories overnight, which then evaporate just as quickly. The point of such theories, if they even merit that label, is not to seek the truth but to defame political opponents and turn victims into villains.
Before he even ran for office, Trump was notorious for promoting false stories about Barack Obama’s birthplace or vaccine safety. Heir to Joseph McCarthy, Barry Goldwater, and the John Birch Society, he is the lurid incarnation of the paranoid style. He routinely damns his opponents as “evil” or “very bad people” and speaks of America’s future in apocalyptic terms. It is no surprise, then, that every member of the administration must subscribe to Trump’s false claim that the 2020 election was stolen from him, or that celebrity conspiracy theorists are now in charge of national intelligence, public health, and the FBI. Former Democrats who hold such roles, like Tulsi Gabbard and Robert F. Kennedy Jr., have entered Trump’s orbit through the gateway of conspiracy theories. They illustrate how this mindset can create counterintuitive alliances that collapse conventional political distinctions and scramble traditional notions of right and left.