Steve Sailer points out the salient point that is never discussed whenever the topic of immigration is broached:
Immigration is probably the single broadest, deepest, most intellectually challenging topic in all of public policy. There’s no knottier or more significant question you can ask than: When the government elects a new people, how many and whom should it elect?
The harsh reality is that everyone, including the most starry-eyed immigrant enthusiast who thinks Guatemalans emit vibrant rainbows instead of methane and jihad-sworn Saudis merely want their shot at the American Dream of a white picket fence and 2.5 wives, believes in limits on immigration. There is no way that anyone is going to cheerfully permit 300 million Chinese to immigrate next year, so the conversation isn’t actually about whether to limit immigration or not, but rather, which immigrants and how many them will be permitted entry. As the old joke goes, we’ve already established what the lady is, now we’re just haggling over the price.
Given the way that many immigrant cultures have actively conspired to significantly modify Constitutional WASP America to suit their foreign preferences, it appears likely that history will eventually judge much of the immigration that was permitted in the previous century to have been a tremendous mistake. And it appears even more likely that this current wave of immigration from the Third World will work about as well for America as Visigothic immigration did for the Roman Empire.