Progressives like to say that a racist doctrine they call “replacement theory” is very big on the right.
I won’t say there is no such theory. There is. Actually, though, versions of the theory are held both on the farthest, farthest fringes of the right and – more quietly – among large, large sections of the left.
The right wing version is that immigrants, especially immigrants of color, outbreed people who were born in the country, so that descendants of the former will “replace” descendants of the latter. This is supposed to be bad.
The left wing version is that immigrants, especially immigrants of color, trend more to the left than people who were born in the country, so that leftists will “replace” conservatives. This is supposed to be good.
Both versions of the theory are nuts.
As to the former version: If the country becomes browner in a few generations, so be it. People who are too selfish to have children deserve to be “replaced” by people who love them.
As to the latter version: Immigrants who are acquainted with the politics of the country are often quite conservative; they don’t want to lose what they’ve worked and suffered to attain. So if left-wingers think immigration will lead to the “replacement” of conservatives by liberals, they may have it backwards.
We like to say that we are a nation of immigrants, and it is true. The real question isn’t, or shouldn’t be, whether immigration is good, but whether chaotic immigration is good. What is happening at the southern border is simply cruel.