Did you … stop reading?
The real die-hards don’t think it’s a scheme to create a permanent Democratic majority; they think it’s a plot to ethnically replace white Americans. At its core, the great replacement is about demographics, not democracy.
The article doesn’t try to rebut this because of the staggering number of premises you need to accept before you can even reach such a conclusion. It’s really not worth unpacking here.
It’s a huge failure of computing that this is the most convenient and obvious way to do this.