White replacement theory is real and is being carried out in several first world nations.
It's a wide-ranging theory though. It goes from just acknowledging demographic changes in white countries. To some evil orchestrated plot to take down whitey.
Maybe it's a conspiracy theory that noticing demographic shifts is now labelled believing it's all a planned genocide.
I personally don't think there are elves or something planning why it is happening. It's just a bunch of economic policies and ideologies at play in the west that are supporting immigration that eventually shifts demographics.
I suspect some come from the world becoming smaller due to all the innovations of the 20th century. There's some level of white guilt about how much better off it is in the west than most of the world. This is then masked with cultural relativism, so people don't acknowledge it is their motivation. Yet it drives their thinking. We should allow more people to live here, it'll be good for them, not that there's anything wrong with anywhere else, it'll just be better for us and for them. They'll become more like us, bring only superficial cultural differences, like cuisine or different clothes for weddings.
People don't know history, understand civilisations and how the good ideas that created prosperity in the west were a long time coming and had to be fought for.
As they don't understand this, with cultural relativism. If you were to suggest the west should work with poor, non-functioning countries to reform their societies and cultures to become more like the west. You'd be told you're a horrible racist and a colonialist.
If you were to say migration to the west only provides incentives for people to want to leave their homeland. Not to improve and reform their homeland. You're denying someone living a better life. Plus all cultures are just as valid.
Even though they are coming from a position of wanting to help more people. Make more of the world desirable places to live. Actually, be a genuine utopia plan, not based on one magically popping up if you tear down enough statues.
Also on replacement theory, I had an awkward conversation the other day about it. They brought up Tucker backtracking, but videos doing the rounds of him talking about it. I mentioned the videos from MSNBC of people talking about it. The other person was all, "what no" and didn't believe me. All "that couldn't happen." I'm like, "well yeah but it is happening though." Just ended the conversation to not get into an argument.
Only after thinking back on it, I think this guy thought replacement theory was not just demographic changes and whatever motivations, evil conspiracies that can be tacked onto that; but literally, the shooter believed a black person was going to come and take over his life and replace him. lol His comments were like, "but who does he think is going to come replace him?" lol