As a legal immigrant, I can assure you, it's not open door. It's difficult, expensive, long and Kafkaesque. You really really shouldn't describe an experience you clearly don't understand.

We could look at what Canada is doing. Plenty of parts of the US are empty, the problem is the angry old man squatting the land.

No thanks. We don't need to cram every square mile full of people.

Yeah, because that's what I was talking about.

> With open door policy that make USA great

The USA doesn't have an open door policy.

And US immigration law for the past century and a half has been largely about ethnic exclusion, such as the "No More Chinamen Act" of 1882 and the "We Have Quite Enough Kikes and Wops Now Thanks" Act of 1924.

How was the US doing as a nation when it was more exclusive?