I think the comment you origionally replied to did.
"Rich liberals" was the phrase.
I personally think it is all about votes and power. People of all walks of life abuse power. Democrats want the illegal alien vote, and that of their kin.
Further, the illegal alien status is held over the heads of tons of people. "Tons" literally means 4000+ pounds or simply informally "a large number," which I think easily exists in America, just from the small fraction of illegal alien clients I see get the shaft. And, yes, a large number are used as sex slaves with little recourse.
Furthermore, I am not even arguing the free labor acquired by simply shorting illegal aliens on paychecks. Many work for 10+ hours/day and get paid for a fraction of that time (citizens too). The time they are not paid for is technically "free labor."
There is certainly an underbelly of society we are all blind to. When you get to a point where you have seen so much you realize you haven't seen sheet, it becomes clearer. Ignorance is bliss.