What it means, where it came from

• Last week’s mass shooting in Buffalo has drawn renewed attention to a racist conspiracy theory known as “replacement theory.”
• The theory is often mischaracterized and confused with demographic changes that are happening in the United States.
• True ‘replacement theory’ posits not just that demographics are changing, but that this change is being orchestrated by a sinister cabal.

A racist mass shooting that left 10 people dead in Buffalo, New York, put national attention on a concept that has alarmed experts in extremism for years: “replacement theory” or the “Great Replacement.”

The attack targeted Black people, and the man charged in the shootings purportedly wrote a hate-filled document nearly 200 pages long, as well as hundreds of pages of a personal diary posted online before the shooting, that cited the conspiracy theory extensively.