"...at the choice of AND for the benefit..."
Undocumented workers ARE HERE at the choice of and for the benefit of us the acceoting country. We need them, we hire them, if they weren't hear small farms would go broke. We need them so badly we ignore the stupid laws that ignore this need.
Thus we force the breaking of the law, and we exacerbate all kinds of bad consequences, among them allowing unscrupulous employers to displace citizens from jobs.