Excellent article Dave Olsen.
It may be argued that the worst offence that wealthy countries do to less wealthy ones is to lock people out. It serves no one well -- certainly not their economies. We should be allowing as many different folks into the country as our infrastructure and systems can handle. Would it mean placing resources into streamlining people into the country? Yes it would, but as you point out in your article the benefits to all Americans (aside perhaps a few that could be compensated in the same way as people hurt by trade) are enormous.
The block in vision is not so much politicians as they are principally weather vanes. It's our friends, cousins and neighbors that need to be convinced that they would be more prosperous and perhaps happier if they welcomed a few strangers.
Much of my political writting includes immigration because it's integrated very much with other issues -- race, religion, politics and I'm sure sex as well. Short articles (based on writing in NYT) "We Need Outside People to Help Us" and "A High Wall with a Big Gate" are here on Medium.
Many thanks