How do I deal with a prejudice mother living in a diverse assisted living facility?

My mother is very prejudiced and will have to live in a very diverse assisted living community and will, most likely, have a roommate she is prejudiced against. She has always been this way, but I believe she has gotten worse as she as gotten older, and I am both angry at her and concerned for the people she mistreats. She now wants to either move to our house or move to another place, neither of which is possible financially or physically. I can't even talk to her about this - she just gets mad! Any thoughts would be helpful.