It's a silly thing to say in a middle class, office context, but having done manual labor for a couple of decades in the Sixties, Seventies, and Eighties, I don't think it's a crazy claim when it comes to manual labor. Native born Americans are far less willing to undertake careers in the trades. It's a looming crisis because it's already hard to get skilled tradesmen and getting worse fast. I laugh at the Trumps of the world who talk about closing the country to immigration because, who exactly do they think is doing the manual labor even now? Here in Northern New Jersey and New York City, I see almost no American born tradespeople, domestic workers, kitchen workers, etc. Most are Mexican, Central American, or from the Islands. The few who aren't are often Irish or from one of the Eastern European countries, particularly Poland. I haven't seen a native born American construction worker anywhere near where I live in 13 years. It wasn't at all like that when I was starting out---the demographic of the trades was pretty much the same as the demographics of the country, other than that it was almost all male. (There are some women now, but not many.)