Wish I knew the answer to your question. I agree that we can't communicate effectively with euphemisms and part of the problem is that those of us in the coastal cities know few Trump supporters. 

One idea that seems to have sprung up in many heads (including mine) independently about dealing with the situation, if there is a Muslim registry, is to register as a Muslim. (There is a disagreement in my family as to whether we should do this if the registry is only for immigrants-- I will not in that case but other family members will do so.)