It is all in the eye of the beholder. One group of people will say it is politically incorrect to criticize minorities. Another segment will say it is politically incorrect to criticize the troops.
Everyone is politically incorrect in someone else's eyes.
Retarded | Define Retarded at Dictionary.com
It was used to define a person as above, mentally handicapped -challenged.adjective
characterized by a slowness or limitation in intellectual understanding and awareness, emotional development, academic progress, etc.
Slang. stupid or foolish.
(used with a plural verb) people who are slow or limited in mental development (usually preceded by the):
it was also use as a slur.
The terms I have used have evolved from retarded to accurately describe the individual.