Is it legal for a mortgage to be denied or a auto loan due to me

Wildwood - Is it legal for a mortgage to be denied or a auto loan due to me being on low income housing with "Hud"? As soon as I apply for a rental property or am trying for any kind of credit or loan I get denied,not to mention being treated as if I have no right to even consider getting a car loan.The salesman walks away and states he has another customer waiting for him.