Very likely the reader is wearily familiar with one of the memes that American right-wingers endlessly repeat. It's called the "great replacement": the claim that shadowy but apparently omnipotent elites are deliberately replacing the old stock (meaning white) American population with immigrants from predominantly non-white or non-Christian countries.
The notion had its beginnings decades ago in the mental swamps of Southern segregationist politicians and has been recycled in various iterations through white supremacist groups. Donald Trump's election and the popularization of the phrase (in more or less coded language) by professional jackasses like Tucker Carlson made it into another of the Republican base's innumerable slogans.
