The idea of keeping immigrants out of your country is starting to seem outdated. In many cases you need them more than they need you. Obviously you can't let people cross borders all willy-nilly, but the immigration policy in the United States seems a hodgepodge. I say this not because I have studied our immigration policy but because I wanted to use willy-nilly and hodgepodge in the same sentence.
A better immigration policy would be to make the U.S. as inviting as possible so everyone wants in. Then choose the most worthy applicants based on how much they would contribute to the economy, or how attractive they are. And obviously all applicants would have to pass a physical exam so they don't burden the healthcare system.
I know, I know, it smacks of eugenics. The Nazis gave it a bad name. But every corporation hires employees based on some sense of economic worthiness, or in some cases hotness. Why should a country settle for less. Technically we wouldn't be practicing eugenics if our selectivity was based on what a person can contribute today. Improving the gene pool would simply be a bonus. So get over it.
With this sort of immigration policy our competitive advantage would include anything that made living in the U.S. more enjoyable than living elsewhere. We would focus all of our energy on cleaning the environment and keeping crime low while giving people as much freedom as practical. And of course we would want a top school system and lots of entertainment options to keep our new immigrants happy. Everything we did to attract the cream of the immigrant crop would be good for the current residents. It's a win-win.
Canada is already doing something along these lines. They welcome immigrants who have valuable skills. The U.S. can't match Canada in friendliness, crime rates, personal freedom, or the environment. But no immigrant wants to walk around in a snow suit trying to understand French either. So I think we can be competitive with our buddies to the North.