Can a U.S. Citizen sponsor a non relative immigrant?
It would depend on what you are referring to as sponsorship. You can sponsor anyone in terms of completing the affidavit of support to meet the poverty guideline. As far as petitioning for a non-relative, no but you can invite a non-relative to visit you and maybe employment sponsorship can also be attained for a non-relative. I hope this addresses your concerns. It is advisable to contact an immigration lawyer to address any other concerns you may have. You are welcome to use the link provided. Goodluck.