[WalterBright]

I'd like to see a case where it worked.

In any case(!), the economic principle at work here is the law of comparative advantage.

https://www.investopedia.com/terms/c/comparativeadvantage.as...

To claim that protectionism improves prosperity is to claim that the law of comparative advantage is incorrect.

[conanbatt]

I shed a tear in Ricardian.

Of all the purported liberal ideas the U.S. thinks it embraces, restriction of immigration is one of the most baffling.