I consider myself politically progressive, but there are a few major sticking points that keep me perpetually at odds with my would-be allies. I hold in utter contempt anyone who would attempt to dictate to me a list of things I am forbidden to say, and it is generally more from the left than from other quarters that such dictation comes. I am part of that minority that continues to consider political correctness a real threat, and not a momentary excess of the early 1990s, when we heard all that reactionary huffing about how soon enough they'll be making us say 'vertically challenged' instead of 'short' and so on. I speak not with Rush Limbaugh but with Vladimir Nabokov when I say that I am horrified by the limitation of free expression, by which I don't mean the usual 'expression of unpopular ideas' beloved of 'card-carrying members of the ACLU', but rather the creative use of language where a Schillerian free play of the imagination is the only source of regulation. I believe the desire to regulate externally stems not just from a misunderstanding of how political progress is made, but also of how language functions.
...If my would-be political allies were being grown up about these things, they would understand that what they are really after is not something that can be attained by setting down, once and for all, the complete index nominum prohibitorum. Rather, it is a matter of cultivating virtues like tact and discretion: virtues for which there are no easy rules to be mastered in an a priori way, but which always depend upon the combination of a million different social cues.
"The desire to regulate externally" being, in my opinion, the heart of it. Most of the progressive linguistic police I've encountered are extremely distrustful of the anarchic, nebulous nature of language, as they are with anything that doesn't fit neatly into their conceptual taxonomy. I've heard that tendency described variously as "rationalism" or "theorism", but I've started thinking of such uptight people, progressive or reactionary, as Procrusteans. Above all their professed causes, they care most about the internal consistency of their worldview, the supposedly clear, strong connections between their axioms; they're happy to stretch or amputate any inconvenient facts or realities as needed.