"Core rhetorical tactic of the progressive left". Or the conservative right, depending on which side of this divide one happens to stand on. And speaking of Orwell, he was pointing out the doublespeak of the Fascists, not the socialists.
Fascists are the ones who want to manipulate other people to their Fuhrer's will. To do that they must manipulate language. Whereas "socialists" are about the common good, which can only happen through peaceful co-existence, which can only happen though democracy.
Depends of course on which definition of "socialism" you use. Didn't Hitler call his movement socialism as well? But I always associated "socialism" with "being social", which means taking into account other people's benefit as well, instead of trying to overpower them with propaganda and double-speak (and of course, violence).
If the goal is unlimited power to your party, to your leader, it would only make sense to lie to people as much as you can, to mislead them. To double-speak to them. If your goal is peaceful co-existence, then not so much.
And where there's smoke there is fire. Where there's Double-Speak, fascism is not far away.
Ironically Double-Speak succeeds because people are social beings, they really WANT to agree with others.
"Illegal alien" is one of the greatest accomplishments of language engineering and was unambiguously successful.
When the left tries this today it results in equal and opposite backlash and has no effect in terms of policy, winning elections, and that sort of stuff, but it certainly can be a motor that keeps online bubbles bubbling.
I think there is no equivocation or ambiguity here, unless you are me at age 5 asking why aliens have landed in Mexico.
I would hazard that you are underestimating the impact of these rhetorical tactics, but I've not the energy to aggressively litigate and cite this point further.
The effectiveness of these tactics is incredible, it helps people who build an identity around marginalization to always feel marginalized. If they ever won anything it would threaten their whole reason for existence.
Again, I think this is likely seen differently depending on which side of the political spectrum one stands, and what sources of information one attunes to. I agree that both 'racism' and 'gender' have become flash-points for discord, and that one can point to the left as trying to change the definitions. But I can think of other words that the right is equally guilty of attempting to re-define. For example, 'woke' was a term originally rooted in African American communities meaning awareness of systemic injustice, but is now used by the right as pejorative for anything they disagree with. (Including the existence of systemic injustice, sigh.)