Some years ago when the right wing crazies had their UniteThe Right Hate Fest in Charlottesville VA we were treated to the sight of torch bearing wing nuts marching and chanting "Jews will not replace us" over and over. I remember being puzzled by what they meant by "replace". Since then the far Right has echoed with claims that the white majority of Americans might be "replaced by a tide of nonwhite immigrants who "don't look like America".
Now we find that the cretin that shot up a supermarket in a black neighborhood in Buffalo NY told police he was motivated by a fear that immigrants of color were going to "replace" white (European) Americans as a political/cultural majority. As crazy as it is this notion has been around for some time. Racist firebrand Pat Buchanan used to complain about American culture being smothered by aliens coming across our Southern borders. He would rail at the notion of a bilingual America where English and Spanish would both be spoken.
The "Great Replacement Theory" has gained popularity in recent years as Trump and his MAGAites have cultivated hatred of immigrants but no one has done more than Super-White Preppy-ass Tucker Carlson of Faux News Channel whose misuse of the First Amendment has written new chapters in the promotion of racial discord.
The Dirtbags at FNC and Carlson himself will ride this horse for all it is worth and there isn't much we can do about it except pressuring their advertisers to withdraw their support. It's worth I try, it worked on O'Reilly and a couple of others IIRC.
It occurred to me that the promoters of this evil notion have it exactly backwards. All through history influxes of white immigrants have displaced black, brown and red natives from their lands. It's happened in Australia and New Zealand, in South Africa, in Zimbabwe (once named Rhodesia after a white Briton). Nowhere has it happened more than here in the US of A (and Canada) where a tidal wave of white Europeans "replaced" the indigenous populations and stole their land, their cultures, their languages and their religions.
That being the case Carlson, Buchanan, Trump and the rest of 'em oughta just Shut The Fuck Up!