I live in the midwest. Legal, non-migrant citizens plant and harvest the food that grows there. And it's all done by machine, anyway. The use of abundant amounts of illegal cheap farm labor for certain kinds of farm crops retards technological development in those areas of agriculture.
In addition, importing an ever-growing, heavilty criminal, uneducated, unassimilable, resentful, dependent, peasant underclass from a politically corrupt third world country is a recipe for social, cultural, and political disaster in this country.
The shamnesty politicians wouldn't even promise to get rid of the illegal immigrant felon population! At least they were honest, which astonishes me.
What do the elites and their few, deluded supporters care? It's job security for them.
Similar to ancient Rome and Greece. The Industrial Revolution could have occurred much early (in those two civilizations, amongst others), but with slaves, the machines didn't seem quite as impressive.
Especially in the case of Rome. There were supposedly ideas for machines to help in....(construction?), but it would concluded that if the slaves weren't kept busy, they might revolt. So the plans for the machines were tabled.