I’m sorry, Mark, but I don’t see how you can reconcile your stated belief in free-market principle with your suggestion, in response to Jonah’s reasonable point about factory wages and international competitiveness, that the examples of Florida citrus growers and Fresno raisin farmers prove reliance on cheap labor is harmful to business. You say that “lax immigration policy allowed them to blithely continue using old-fashioned, stoop-labor methods” rather than playing to America’s competitive advantage in capital and tech. What you apparently mean is that government should coercively restrain businesses from choosing one competitive strategy in favor of another that you and government officials apparently believe is superior. What makes a strategy or factor a competitive advantage? If businesses, choosing freely among alternatives, finds that strategy or factor to maximize return on investment. If these decisions are warped by taxes and restrictions — what you are proposing, let’s face it — there is no valid way to know what the underlying economics tells us about comparative advantage in a particular case.
To suggest that current immigration policy “allows” businesses to make the “wrong” choice in how to make and sell goods and services is inescapably to suggest that government policymakers know better than entrepreneurs and managers how to operate businesses. That is empirically false (on average, of course) and remarkably statist of you.
That’s not to say there might be other reasons to adopt a more-restrictionist policy on immigration. As John D. properly notes, there is more at stake than economic efficiency and productivity. Society and economy are not synonymous. Welfare costs, security, public health, social cohesion — all legitimate concerns. But your argument here sounds an awful lot like industrial policy.