This is a lump of labor fallacy - importing workers increases your salary because immigrants, being prime-age consumers with complementary skills to the natives

This is a lump of labor fallacy - importing workers increases your salary because immigrants, being prime-age consumers with complementary skills to the natives, increase labor demand more than supply. (They don't have complementary skills to themselves, so they're more likely to suppress wages of other immigrants - so you could say the rational thing would be for them to shut each other out and you to encourage it.)