Shot:
they are a legitimate threat to freedom and to anti-authoritarian leftists,
Chaser:
we shouldn't allow these people to exist in the internet free
https://old.reddit.com/r/tankiejerk/comments/197l9ik/tankie_is_not_offensive_anymore/
I was thinking about this and it occurred to me that, besides "buzzword", a term that people use that seems to specifically line up with what you've talked about is "scare word", a term that is annoying to research for obvious reasons, but we can find an attestation of its use to describe political rhetoric here and there.
A few more:
https://www.npr.org/2019/04/24/716728643/socialism-isn-t-the-scare-word-it-once-was
https://www.snopes.com/fact-check/truman-socialism-scare-word/
Hope this helps. I also saw "scare term" and "devil word" referenced in a pop-linguistics article.