Late on Election Night in 2012, the nation watched as Karl Rove panicked on live television. Fox News, his post–Bush administration sinecure, had just called Ohio—and, by extension, the country—for Barack Obama. While the network broadcast images of jubilant crowds in Chicago, Rove refused to concede. “This is premature,” he insisted, ticking off various precinct figures from Ohio counties and warning that everyone needed to be “very cautious about intruding into this process.” For an embarrassingly long half-hour, Rove argued with the entire network, demanding that Fox retract its call on Ohio, to no avail.

What did Karl Rove know that no one else did? Why was he so certain that the numbers from Ohio were wrong? The left-wing web site Truthout thought it had the answer. A few days after the election, the site published an article asserting that Rove had been working behind the scenes to rig Ohio’s electronic voting machines, monkeying with the software to tilt the count to Mitt Romney, as part of a conspiracy to rob Barack Obama of a second term. He’d done this before, the site charged, back in 2004, to assure Bush’s reelection. That’s why Rove appeared “genuinely shocked” when Obama took Ohio, “because he knew the fix was in, just like in 2004, and there was no way President Obama was going to win reelection.”

So why hadn’t Rove’s ratfucking scheme worked? Because, Truthout claimed, the hacker collective Anonymous had learned of his conspiracy, and had secretly out-ratfucked the ratfucker. Citing a YouTube video released before the election, Truthout described how Anonymous had warned Rove not to act: “We want you to know that we are watching you, waiting for you to make this mistake of thinking you can rig this election to your favor.” Truthout, if correct, suggested an awful truth about our political system: A shadowy organization of superhackers was the only thing standing between us and a stolen election.

For the most part, this kind of conspiracy theory—the idea that sinister forces are secretly engaged in a host of elaborate plots to manipulate virtually every aspect of our lives—has been fairly rare on the American left. Sure, liberal nut jobs have engaged in all kinds of far-fetched theories over the years, wild ideas about the Trilateral Commission and the JFK assassination, that the government created AIDS to destroy the black community, or that George W. Bush had advance warning of the terrorist attacks on September 11. But most of these theories have remained cordoned off from mainstream media; the Truthout story, for example, never circulated much beyond a few fringe web sites. The left has generally presented itself as the sober, rational half of our political discourse, eschewing paranoid fables and histrionic bloviaters in favor of reputable, fact-checked reporting.

The right, on the other hand, has not only incubated conspiracy theories, it has thrived on them, become dependent on them, built entire media ecosystems and political careers around them. Glenn Beck, at his peak, commanded a daily television audience of more than three million viewers by arguing that the Obama administration had secret plans to implement a Second Bill of Rights, that the Arab Spring was the beginning of a worldwide Muslim caliphate, and that Woodrow Wilson and Teddy Roosevelt orchestrated a 100-year conspiracy to establish a “socialist utopia” in America. Alex Jones, the founder of Infowars, has become an influential voice on the right by insisting that the Sandy Hook massacre was a government-led false flag operation to implement gun control, that same-sex marriage stems from a “eugenicist-globalist” worldview, and that Hillary Clinton and John Podesta ran a child sex–trafficking ring out of a pizza parlor in Washington, D.C. None of this stopped Donald Trump from calling Jones for advice and appearing on his show. After all, the two men helped promulgate what is perhaps the right’s most influential conspiracy theory—that Barack Obama was born in Kenya, a racist fantasia that launched Trump’s political career and helped land him the presidency.