Mealy-mouthed attempt at getting people to avoid superficial expressions of bigotry, which ends up debasing the language without dealing with the stupidity underlying most hates and fears. Merely ends up giving the bigots one more thing to snarl at and, yes, it really can impose a tyranny of its own. Many examples of allegedly common politically correct speech are urban myths ... which we could still have done without.
Some (real and imaginary) examples of political correctness:
You're not black (in the USA), you're African-American.
(As Whoopi Goldberg once commented, and I may be paraphrasing, "My ancestors didn't come through generations of the slave trade and the Civil Rights movement to end up hyphenated.")
You're not crippled, you're differently abled.
You're not a member of the Undead, you are biometrically challenged.
You're not an android, you are an artificial person.
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