Family is Family, And Business is Business, And the two shall never mix, Especially those of us who are immigrants where our culture depicts that your extended extended extended family are as important as your nuclear family.   

Legal immigrants to the US can get drivers licenses, social security cards, and have been vetted before coming to the U.S.

You don't need this at all because if the police or immigration/DHS come asking you have to give them information anyhow.

Our 4 tenants are immigrants and English is not their first language.We did not want to continue to pick up the rent for many reasons.We opened an account at a Bankm with a branch  very near them and asked them to bring their rent to the bank on the  1st of every month.  

You can put whatever you like in your contract, but if it falls under the category of what the law deems to be an Unfair Term it will not be legally enforceable.This is the  UK publication entitled Unfair Terms in Tenancy Agreements.https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/284440/oft356.pdfHere's what it says about forcing your tenant to buy renters insurance.unnecessary insurance requirements - we consider that whether tenants wish to insure their own personal belongings is a matter for them and that it is unreasonable for the landlord to make this a contractual requirement.

However lets say it does, many illegal immigrants have multiple people in their home.

Lots of good people out there that don't qualify for conventional mortgages that would treat the property better and fix it up, specially immigrants like myself.

Immigrants in lower income, in particular, can be very respectful and dependable renters if you screen them right.

I want to say that immigration status is a protected class in Fair Housing.

I don't know whats going to sustain this because middle income wages are not growing as fast as rents.If there is a dynamic such as high immigration rates then maybe it will be okay.I would agree if its not a good deal today I wouldn't count on it being a good deal in 10 yrs.