This might actually work if we controlled the flow and strongly encouraged integration via the old melting pot method. However, the current elites are leftists who believe the multi-culti nonsense. So instead of maintaining a youthful US population, we will instead get youthful Pakistani, Somalian, Mexican, Chinese, etc. populations who will either ignore one another or be at odds in increasingly violent way.
Japan's slow suicide will be a party compared to what is bound to happen in Europe and the US if the current migrant flows continue.
Thanks to Scotus’ social justice rights to chemical contraception, abortion, and buggery, one generation has the power to eliminate the next, and with it, the republic.
An institution designed to adjudicate the law is an enemy within, the most powerful and destructive enemy we, and Western Civilization have ever faced. It must be stopped.