Lets imagine for a moment we allow the free trade phenomenon of American exogenously financed consumerism to continue to global equilibrium, how much wealth will the country have left?
Many prominent American investors; notably Warren Buffet, George Soros, and Jim Rogers; vocally oppose these ideas.
Academic theories are good fun, but we ought to slow down and act pragmatically. A perfectly free market is just too ugly.
One wise measure of pragmatism may be to adjust the H-1B quota downward as the domestic labor market contracts to maintain the status quo (as far as I can tell this is what the discussion is really about.)
edit: Also, I feel the immigration question is more nuanced than the "classic make-work fallacy," which is a lot closer to breaking something with a hammer and feeling good about creating a job for the guy who glues it back together.