Ken Loyd, a friend and fellow pastor of the homeless here in Portland had an incident with the police the other day. It wasn't that big of a deal, but some of his homeless friends were sitting on a bench which was part of a police memorial. Someone called the police who said that they were littering, and the police discovered that it wasn't really true, but they still told the homeless not to sit on the memorial. They weren't harming the memorial and there is a bench there to sit on.
Ken was musing about this and he said, "I realized from this that from their perspective because the homeless were touching the memorial they made it unclean. Now I understand that we do have an unclean class in our society. The homeless are the lepers of our society."
Creating an unclean class is a stage in dehumanizing them.