Employers hire invaders because they’re cheap labor and they don’t complain about work rules or conditions. The idiots thought they were there because it’s jobs US citizens won’t do. They got what they deserved.
A few years ago a meatpacking plant in Iowa was raided by INS and so many were detained they had to shut down. They then advertised for American workers and had the place fully staffed and running in a week or so. Of course they had to pay higher wages.