in a town of about 33% hispanics. i have worked with (professionally and through church callings) with Hispanics my whole life. Thus, my learning is from that group only. I can't comment on Asians, Africans, etc though , i suspect things are similar. "working the system" is not hard to do for anyone. It happens all the time.

A couple of my observations/comments:

Education... Average US cost of educating a child is betweeen 10-15K per year. Immigrants do pay property taxes in their rent, but, if their house/apartment has only $2-5K a year in property taxes built into the rent, then, they are only paying a fraction of the cost of the education. Throw in multiple kids and you see they are paying a smaller fraction. (BTW, not 100% of property taxes go to schools. So, you have to factor that in.

Food at school. No citizenship is required to get free breakfast, lunch and, in some cases, after school snacks. Schools give them away generously as it actually becomes similar to a revenue source for the school. Schools get more $ from teh state for the number of kids that eat meals at school and for those who get subsidized meals.

Housing.... illegals do use fake IDs regularly. but, even if not, there are many of them who have "cousins" who are USC and who get housing provided. They either 1) invite a bunch of family/friends to live with them or 2) don't live there and let family and friends use the whole place. In both cases the "cousin" usually asks for $. That becomes a source of income for the "cousin". Income that isn't reported or taxed.

Food Stamps ... just like housing. Friend/Cousin can access and sell to the illegals for a % of the cost.

WIC -- very lax checking off citizenship or even income level. show up and be a minority and you can get pretty easy. Just like free school lunches, there are few incentives to reduce the number of people who get them.

Charity... many of the people i've known over the years tell me they simply go to food banks, etc. becuase "why not. they don't even ask me if I really need it. they just give it to me." I'm talking about people who make decent money, drive decent cars and who are living a much better life than the one they had in their home country. They just figure if it is out there for free, why not get it?

Those are a few of the ones that come off the top of my head.