That sounds a lot like picking cotton. If the immigrants don't become Americans (who supposedly "won't do this type of work") then what are they? It sounds an awful lot like keeping slaves. They even arrive crammed in the holds of ships, unable to speak the local language.

Americans will do the work. They won't if an excess of unskilled labor drives down the wages, but that doesn't have to happen. We don't need to keep an underclass.