From pockets in small town Minnesota to Christchurch, New Zealand, a racist conspiracy theory has taken hold—sometimes to deadly consequences. The “great replacement,” also known as “white genocide,” is summed up by its name: a secretive cabal of elites, often Jewish, is trying to deliberately destroy the white race through demographic change in importing immigrants and refugees. Luke Darby writes in GQ that obsession with racial purity obviously goes far back, but the modern iteration of “white genocide” comes almost directly from The Turner Diaries, a racist novel self-published in 1978 by neo-Nazi William Luther Pierce, writing under the pen name Andrew Macdonald. The book is set in a dystopian America where white people have been disarmed and oppressed by non-whites. The book culminates in a white nationalist revolution led by a group called The Order, who go on to plan a global genocide against non-white people. There’s another layer to the panic over demographics: the fear that birth rates for white people are falling all across western nations. The idea was partially popularized in a 2012 book by French philosopher Renaud Camus, and it’s articulated in another white nationalist trope, the “14 Words”: “We must secure the existence of our people and a future for white children.”