US Government designates host of noblogs.org a "global terrorist"

In the original sense, probably yes. In the more current sense, no.

The original sense was something like "unanswerable libel, especially around group characteristics". The most common present sense is closer to something like "disparaging epithet aimed at a group, meant to have universalized negative and/or libellous connotations". A slur in this sense roughly means "a member of this group, which, I chose this particular word as a way of reminding you, makes the person despicable and omniwrong regardless of anything else". That's what "pejorative" means.

If you call TESCREAL, or a component of it, a "cult", you're first evoking the idea that anybody who falls under "TESCREAL" umbrella is already bad (as all right-thinking folk already perceive). Then you're perhaps proposing or emphasizing a particular way everybody should think they're bad (it's a cult)".

It's also wrong and dumb. Some of the components of "TESCREAL" may have shared weird beliefs, and even shared weird social rituals. That's not what a cult is, not even close. Not in modern speech outside of academic history and folklore. And even if they were cults, they would not all be the same cult.

> Or calling out the outsized, malign impact they're having?

That kind of frothing is a better example of the original sense, if still not of the new sense. Vague imprecations that can't be defended against.

Nobody identifies with "TESCREAL". If you look at all the people who do identify with any of the labels that go into it, you end up with a pretty diverse group. It's even possible that that diverse group has more fascists in it than there are in the general population. Fringe groups tend to have fringe members who are members of other fringe groups. But fascism is neither a majority characteristic nor a defining one.

By the way, "fascist" itself is a slur when used to mean "anybody whose politics I don't like in certain ways", or when used to imply that fascists are universally bad or wrong in some way not directly related to their fascism.

"Fascist" is not (usually) a slur when applied to say, Elon Musk. He's actually in the group; his publicly avowed politics are largely compatible with Mussolini's version (with probably some minor quibbles about business independence)... and even more compatible with Umberto Eco's definition, which is what a lot of people go for these days. More importantly, when people call Musk a fascist, they are pretty clearly calling him out for the particular stuff he has personally said or done to earn that particular label, not about some unrelated issue. And most of them are doing it in conjunction with saying, or at least alluding to, something identifiable and substantive about policies, not just throwing it out there in an unrelated context.

If you were arguing with Musk about the best flavor of ice cream, and you suddenly came out with "What do you know about ice cream, anyway, you fascist", then you'd be using it more as a slur.

As another comparison, if you called Musk a "rockspider", that would be a slur. The word carries specific meaning; beyond marking "a member of this group", it adds "of which, I chose to use this particular word as a way of reminding you, you are supposed to automatically dislike all members". Also, insofar as it does have a well-defined meaning in terms of who falls in the group, you'd obviously be stretching to apply it to him, which would make it especially obvious that you were trying to use it as a per se insult. Actually I think he may be far enough outside the group that the insult wouldn't even land; no actual Boer ancestry, and too upper class to boot. I'm not up on South African slang.