The US in particular has always been made up of immigrants. I don't know how it works for canada. But for the US, that's always been the case. We're a country by immigrants, for immigrants. An American identity is not one of skin color or race. To suggest otherwise is not just a ahistorical, it's anti-American.
There is no mind virus. People wish to rewrite history to fuel their own delusions. They don't require enforcement around immigration, they require medication and perhaps a history lesson or two.
Measured as a percentage of population, we have more immigration now than we did in the 1890's peak. Given our drastically larger population, this is a problem.
Suicidal empathy mixed with this 'idea that america is illegitimate' cause we are a 'nation of immigrants', and we 'took land from the natives' is quite frankly retarded. And i can use the word retarded because i mean it in the literal since, "a verb meaning to slow down, delay, or impede a process."