And what can this 'cheap labor" do? Not much, that's why they are cheap. As for the standard of living, that's ridiculous. Americans have a high standard of living because their labor is worth a lot because they are educated and skilled, not because they are Americans. It is frightening how little econ people know.
Most people are of average intelligence and do repetitive jobs. Jobs any illegal can do. And if allowed to, will.
Not much, that's why they are cheap.
They are cheap because they are plentiful, expendable, and are paid under the table with no taxes, social security, unemployment insurance, health insurance, etc.
It's frightening how little econ you know.