If you find your ideology in the mouths of authoritarians, fascists, or those with genocidal intent, it's probably worth reflecting on why.
https://www.reuters.com/world/us/what-is-the-great-replaceme...
> WHAT ARE THE ORIGINS OF 'THE GREAT REPLACEMENT'?
> It is thought to have its roots in early 20th century French nationalism. It was popularized in recent years by French writer Renaud Camus who believes immigration from Africa and the Middle East will eventually lead to the extinction of the native white European race, according to non-profit organization ADL (Anti-Defamation League.) Because many white nationalists in the United States and abroad believe Jewish people are actively encouraging non-white immigration, the false narrative is considered anti-Semitic, the ADL said. White "replacement theory" and the idea of a "white genocide" were a pillar of Nazi Germany's ideology, which pointed to Jews as the single most dangerous threat to white civilization. The Nazis killed six million Jews in World War Two.
https://en.wikipedia.org/wiki/White_genocide_conspiracy_theo...
https://en.wikipedia.org/wiki/Great_Replacement
The author of your book is fascist: https://en.wikipedia.org/wiki/Eric_Kaufmann
> Kaufmann identifies as a national conservative.[13] He has called "woke" ideas "a battle for the foundations of our civilisation" and has expressed support for Florida governor Ron DeSantis, arguing at the 2022 British Conservative Party conference that the party should follow DeSantis's lead.[14] For Kaufmann, although some of his educational policies "go too far", "DeSantis is the future of conservatism".[15]