Well, 999,999 times out of a million, the term "politically incorrect" used today refers to ideas, expressions, etc. which are at variance with the hyper-liberalized industry of American socio-politics.
The example of abortion being "politically incorrect" a hundred years ago is taking a very literal meaning to the term, and one which, though literal, has virtually no import.
"Politically incorrect" is more or less a catch-all for decency and common sense, both of which are oppressed from all directions by political and social elites. If politicians and socialites were good Catholics, the term would probably fall out of fashion, as there'd never really be an occasion to use it.
I do agree with you that censorship is not evil, and is a very useful and even good tool. Like any tool, it can be misused. Censorship of the truth-- which is probably what most Catholics on a forum like this would be referring to when using the term-- is a terrible thing.