I'd be careful about calling it a "huge flood of illegal immigrants," as if those folks just sorta came here unbidden. They don't: Americans pay them to come here.
I think in a sense it's a slightly different form of outsourcing for things like agriculture, while still maintaining the production facilities (i.e., the fields) within the US.
The lessons here are pretty obvious, if unpleasant:
2) By choosing to outsource, American businessmen so focused on short-term results that they cannot see the long-term implications of lesson #1.
To a corporate exec, nothing exists outside of this quarter, and even if it does they take it so seriously they have to meet to discuss it at a titty bar.
Invariably, they think the path to prosperity lies in firing as many people as possible.