Sorry, but  having a little grounding in academic Social Psychology, I have to say that most of the remarks about the immutability of prejudice simply contradict all accepted models in this regard..
Prejudice is an attitude acquired by the subject as part of their socialization, and is therefore almost wholly dependent on the values imparted, mainly from parents / close family.
To deny that prejudice and attitudes towards it doesn't change over time is, IMHO, utter and unrealistic and un-proven garbage, and is hardly a realistic topic for serious contemplation / study.