Negro, black, African-American, person of colour.
Imbecile, idiot, mentally retarded, mentally challenged.
Chinaman, oriental, Asian.
Crippled, handicapped, differently-abled, physically challenged.
Indian, native American, First Nations person.
It seems that social leaders who succeed in changing the accepted terms for victim categories have rejected George Carlin's contention that it is not words themselves that injure, but the intent behind them.
Thus, when a term begins to be used in a disparaging way (for, after all, its underlying meaning has not changed: a black man is black even if you call him African-American), it is reasoned, a new term must be subsituted--one that, being new, does not have insulting associations.
Yet, this process is obviously futile, for the small-minded will simply use the new term with contempt, advancing the cycle.
Do you think this explains the shifting terminology?