Replacement theory checks many of the boxes of useful racist ideology. Most of all, it presents White people as the victims of a plot. Their anger and resentment, in this theory, are natural reactions to the cultural aggression of the other side. Their failures and suffering are no longer their fault. There are always enemies to blame. The future of White, Christian America is at stake. Those willing to fight for it, in this self-justifying myth, are heroes.

Do the purveyors of replacement theory bear some responsibility when their revisionism motivates murderers? Of course they do. This dispute has become tiresome and pointless. There is no moral world in which those who libel outsiders, justify rage, incite bigotry and allege that enemies have broken down the outer gate are innocent of the likely influence of their words.

And the method of mass killing is not some insane, unimaginable, unknown act of evil — something committed by the demon possessed. Lynchings and large-scale terrorist murder were relatively common features of the post-Civil War political order, designed to intimidate Black people and undo that war’s outcome. If the Buffalo supermarket killer’s motivation was to undo the anti-racism of modernity, he is part of a long, ignoble history of racist killers.