Everything about Immigration has Changed - Except Our Thinking

I was  fascinated by an exchange on immigration on NRO between Richard Nadler and John Derbyshire. (See also this ps by Mark Krikorian.) Let me quote a bit from Richard Nadler's post:

It [the effective enforcement of immigration laws] is not going to happen. The second is, if it did happen, the result would not be more jobs for American workers, but the catastrophic collapse of our rural export industries, and a substantial contraction of many branches of industry that depend on seasonal peak hiring to maintain their year-round staff.

I'm struck at how very suddenly out of date this argument sounds, like a memento from a different time, a little bit of yesterday. The argument that illegal aliens would never return home seemed very facially plausible 24 months ago. But when many hundreds of thousands are returning home, you’d think the plausible prediction would yield to the actual fact. See for example here, here, here, here, here, here, or here among many examples I could have chosen. (H/t Mickey Kaus for the first two.) Likewise, the claim that Americans won’t do seasonal, rural, and agricultural work seems much less true in April 2009 that it seemed two years ago. See here, here and the second half of here. Nor are conditions likely soon to return to those prevailing in 2007. The current economic downturn is likely to leave behind a transformed US labor market. It seems doubtful, for example, that construction jobs will return in the numbers demanded in the 2002-2007 housing boom. The collapse in the value of Americans’ portfolio wealth may imply that future demand for luxury services like landscaping and restaurant meals will be diminished. If the recovery is as weak as experts predict, jobs like meatpacking, janitorial and custodial services may be more attractive to less-skilled Americans. In short, it’s not at all clear that the labor market of the future will have require anything like the stock and flow of very low-skilled labor that the US imported in the 1990s and 2000s. This possibility is something that needs to be considered very seriously as Americans consider immigration policies going forward. And those of us who consider ourselves conservative reformers have some extra rethinking to do – but more about that shortly.