There's no evidence of this. Uncontrolled immigration is what made America great. If there's a problem it causes, it's that it creates a brain drain from the developing world to the developed world; it's often the more talented and enterprising people who leave (though that varies wildly among specific emigrating groups).

> Uncontrolled immigration is what made America great

A massive claim. Care to support it?

As far as I was aware, much of America's success is a simple accident of history, notably: having a massive virtually unoccupied continent with enormous unexploited natural resources, a single unified market with single currency, having no land border with a hostile foreign entity capable of posing a genuine threat, and taking advantage of (or as some argue deliberately creating the circumstances for) the rest of the world being smashed by two world wars.

Yeah, but without immigration during the 19th and early 20th century, the US wouldn't have anyone to work on those resources and the continent would still be virtually unoccupied. The US would have been as empty as Siberia.

So then you admit that immigration was just one part of the puzzle? Or are you asserting that you could take those same immigrants, transplant them anywhere in the world, and have the same outcome?

I'm pointing out that immigration helped rather than hurt the US. The claim that it makes countries poor or underdeveloped is wrong.

Absence of evidence is not evidence of absence.

Are you saying you have no evidence for your claim, but there's a chance it's true anyway? Sure, it could be. But if it happens, it's more likely a coincidence caused by other factors.

> There's no evidence of this

There's a lot of evidence of this. Look at crime rates in Germany and Sweden before and after their mass immigration import.