Can the U.S. Economy Grow Without Immigration?

"While immigration isn’t necessary for U.S. growth so long as the American people are free to exchange with the rest of the world, the rest of the world's inhabitants would likely be more productive if they worked in the U.S. In short, prosperity made great by work divided globally would be quite a bit greater if more of the work was divided up by those people in the United States. That’s really something to think about." ~ John Tamny