On 22 November 2021, a crowd of 100 or so people gathered in Dealey Plaza in Dallas, the site of John F Kennedy’s assassination 58 years before. They were convinced that JFK’s son, John F Kennedy Jr, was about to return, to take his place as vice-president alongside a reinstated Donald Trump, to battle the satanic paedophile cabal that had taken over Washington. Some even waved “Trump-Kennedy 2024” banners. Never mind that JFK Jr died in a plane crash in 1999: these people were credulous enough to believe the QAnon conspiracy theory. When JFK Jr failed to materialise, they promised...