As an ugly conspiracy theory re-emerges, we stand at a "never again" moment. The "great replacement theory" is gaining traction far too close to the American mainstream. This conspiracy theory suggests that welcoming immigrants is part of a plan to replace the political power and culture of white people living in Western countries. As the bishop of El Paso, Texas, one of us is all too familiar with the hate and violence this conspiracy theory has inspired: On Aug. 3, 2019, a white terrorist killed 23 people in a shooting at a Walmart in El Paso. In his manifesto, the shooter mentioned the great replacement theory and said he feared a "Hispanic invasion of Texas."