The man who bludgeoned former House Speaker Nancy Pelosi’s husband with a hammer last year consumed a steady diet of right-wing conspiracy theories before an attack that took place with the midterm elections less than two weeks away.

As the 2024 presidential campaign heats up, experts on extremism fear the threat of politically motivated violence will intensify. From “Pizzagate” to QAnon and to “Stop the Steal,” conspiracy theories that demonized Donald Trump’s enemies are morphing and spreading as the front-runner for the 2024 Republican nomination aims for a return to the White House.

“No longer are these conspiracy theories and very divisive and vicious ideologies separated at the fringes,” said Jacob Ware, a research fellow at the Council on Foreign Relations who focuses on domestic terrorism. “They’re now infiltrating American society on a massive scale.”