In early April, Congress held its first hearing on white nationalism since the deadly 2017 “Unite the Right” rally in Charlottesville, Virginia. What was supposed to be an opportunity to address the rising threat of far-right extremism was, at certain points, upended by conservatives who insisted the real threat came from the left.

Brenton Tarrant, the man accused of murdering 49 worshippers and injuring dozens of others in two New Zealand mosques Friday, posted a manifesto steeped in white supremacist propaganda and references to “white genocide,” a belief that white people are being systematically replaced across the world by non-whites.