When swirling charges of rigged elections, witch hunts, and a coup plotted by the “deep state” are referred to as “conspiracy theory,” this is not just a misnomer but a misunderstanding, one with consequences. Conspiracy and theory have been decoupled; we face the distinctively malignant phenomenon of conspiracy without the theory. Like all conspiracism, it rests on the certainty that things are not as they seem, but conspiracy without the theory dispenses with the burden of explanation. We see no insistent demand for proof, no exhaustive amassing of evidence, no dots revealed to form a pattern, no close examination of the operators plotting in the shadows. Instead, we get innuendo: Some government agency “has an agenda.” Or it takes the form I’m just asking questions. Or, most often, conspiracy without the theory is bare assertion, “rigged!”—a one-word exclamation evokes fantastic schemes and the awesome capacity to mobilize three million illegal voters to support Hillary Clinton for president.

When President Donald Trump tweeted that President Barack Obama had ordered the FBI to tap his phones, his evidence was “A lot of people are saying they had spies in my campaign.” What substantiates this sort of claim is what happens next: People repeat and retweet, forward and repost and “like.” Asked whether George Soros was funding the so-called caravan of refugees trekking northward to the U.S. border, Trump replied: “I wouldn’t be surprised. A lot of people say yes.” Instead of scientific validation—evidence and argument—he tendered social validation: If a lot of people are saying it, it must be true enough.

Conspiracy theory of the sort Richard Hofstadter associated with the paranoid style in American politics has always been with us. Sometimes far-fetched, sometimes accurate, and sometimes a vexing mix of the two, classic conspiracy theory tries to peel away deceptive masks to show how the world really works. It demands a cause proportionate to the dire effect. So-called truthers say that the U.S. government must have been involved in or forewarned of the plan to attack the World Trade Center and the Pentagon in 2001; the terrorist attack could not have been the work of 19 men plotting in a remote corner of Afghanistan. To look at a website such as Architects & Engineers for 9/11 Truth is to encounter putative facts, inferences, and conjectures that mimic the methods of scientific research. Insisting that the truth is not on the surface, conspiracy theorists engage in a sort of detective work. Once all the facts—especially facts omitted from official reports—are scrupulously amassed, a pattern of clandestine machination emerges.