My beef isn't with illegal immigration per se, it's with illegal immigration of people that possess sub-100 IQs. If we didn't have an offset from Asia, then we might be in trouble. However, if one were to return in 100 years or so, the bell curve spread will probably have the same characteristics as today, with the only difference being the ethnic makeup.
The US basis of law/culture/society allows certain individuals to excel. I think there will be enough inventiveness and economic growth to absord low-skill laborers. The pity was that we couldn't reach a new level of performance, but then maybe that's the way it has always been.
Unless you can effectively block out immigration like Japan, you'll be taking a step back for every step forward.
Either you are a case study in subtleties or you have changed your views. A few posts ago you talked about how America will become more like Brazil and American culture as we know it will end. Now you appear to be saying we will muddle this mess and trend water through the dramatic demographic changes.
Its all idle speculation I know; and your concerns closely mirror mine. I do find it rather perplexing though.