Replace "political correctness" with "being polite" and pearl-clutching about thoughtcrimes and the death of democracy seems absurd. Can someone explain how the two differ?
Here's one concrete example: during one of my company's all hands meetings our head of HR and head of Diversity gave presentations about our diversity numbers and diversity hiring policies. One of the top voted audience questions was what the company says to people who point our diversity policies constitute lowering the bar for diverse candidates (I actually discussed the question with the person who ask it. He wanted to give HR the opportunity to say something along the lines of "we do have different hiring policies for diverse candidates, but we still ensure all offer recipients are qualified.") Our head of HR denied that we lower the bar, and furthermore said that this question is hurtful. This is an understatement, she basically publicly shamed the asked of the question. The thing is, our company does lower the bar. We allow diverse candidates from "non traditional" backgrounds (coding boot camp, and new grads from non-tech related majors) to apply while non-diverse candidates from such backgrounds are automatically rejected if they don't have a referral. In our phone screen, non-diverse candidates get one chance to pass, while diverse candidates get a second if they don't pass on their first try. I think we don't intentionally hire any unqualified applicants, but to say we don't lower the bar is objectively false. We do indeed set explicitly more permissive hiring policies for diverse candidates. I wanted to ask what HR means when they deny lowering the bar given that we have policies explicitly to that effect. But it was clear that the company had constructed a view of politeness the in which pointing this out was unacceptable - I'm taking unacceptable to the same degree as calling a female co-worker a "bitch". So the result was that our head of HR was allowed to lie with impunity due to a politicized construction of social norms.
That is what I would call "political correctness". I agree that it's a subjective and murkey boundary, but I would draw the line where a group is constructing a view of social norms that has the effect of constraining valid political discourse. Of course this effectively passes the buck to the other question of "what is valid political discourse?" but I think at least 80% of people would agree that affirmative action is valid political discourse. Let alone pointing out when lies about the company's policies are being promulgated by staff.
When "politically correct" is used as an attack on someone else's words, it nearly always means "being polite to a person or group the attacker dislikes".
When "politically correct" is used by a small number of academic theorists to describe the conscious substitution of vocabulary in order to conform to a particular subculture, it means... what I just said.
There are a reasonably large number of people who think that the second definition describes every situation actually covered by the first.
If person A describes person B as homosexual" or "African American" instead of "gay" or "black" instead of in order to not offend person C who is straight and white is that an example of being polite or political correctness?
I would say the latter.
Is it an "attack" on immigrants to approve of Republicans' immigration policy?
Is it an "attack" on women to say that a 20-25% representation of women in tech is an acceptable figure?
There are many places (the company at which I work, for one) where such statements genuinely are seen as attacks.
While it's true that abject denigration and truly extreme political views (I'm talking actual white nationalism, or nationalist socialism here not what is usually referred to by flippant usages of the word "Nazi") deserve to be socially rejected. In that sense political correctness is good. However, I think a substantial amount of what we PC advocates try to pass off as basic respect is constraining valid ideas. And that has the consequence of a handful of people thinking their views are the majority when they really aren't.