And I would agree with all of those points except the last. Again, I have personal knowledge in the area, and I would say that most illegals work for other illegals. Not by much, but more than 50%.
Typical scenario:
Jose comes to the US and gets a job as a laborer in the masonry trade, even though he is a skilled mason. He works hard, saves a little money and makes some contacts, then goes into business for himself. It is out of his pickup, of course, and he is a sub for legal companies, but he is a business man. He recruits and even pays to bring in more illegals and employs them. No taxes, no workmans comp, just cash on the barrelhead. By my educated guess in the Central Texas area, 90% of new homes are built with this form of illegal business and illegal aliens.