I was just thinking the other day: The idea of sanctuary cities comes from the Bible, in Numbers 35. (They are called cities of refuge.) For a long time in history, it was churches and monasteries that gave people sanctuary.
I just wondered if anybody tried challenging all the sanctuary cities by pointing out they are violating the "separation of church and state." After all, it seems that if the idea comes from the Bible it cannot be used in politics .. at least according to some.