Are there studies on whether either the US left or right make more use of snarl words?

Question

In my last question, I attempted to avoid any answer saying that one political party was more likely to abuse snarl words without proof as I deemed such an attack plausible and unconstructive to my question if I didn't exclude it. That led to...debate over my attempt to avoid such a detour and accusation of supposed bias on my part. I'm all for open debate and if people want to make such a detour I'll go along with it — so long as it's backed by science and statistics!

So now I'm asking for any evidence as to whether either side of the US political spectrum makes heavier use of snarl words than the other. I am not asking for opinion, I'm asking for evidence. Ideally, that would be a peer-reviewed study with a sufficiently large sample size. I'm willing to be a little lenient with what I would accept since "snarl words" are hard to define, which may make a perfect study difficult to find; I'd rather have some sort of answer to no answer at all. Still, my final selection will be based on which answer came closest to answering which, if any, side of the political spectrum makes more use of snarl words in their rhetoric and which I felt had the most statistically sound evidence of their claim.

I'm going to request no pure opinion or "that's just obvious" answers or comments if they are not backed by some form of evidence. Links or it didn't happen. ;)

I'd accept research specifically on Republicans/Democrats or more generally on "left-" or "right-leaning" sources.

For my own two cents, I'll throw in one study that concluded Democratic presidents used snarl words more in 2000 & 2004, but Republicans rallied with a huge reliance on them in 2008. Since it's only looking at presidential debates and only the three years, I deem it rather limited evidence by itself to draw much of a conclusion, but it's at least a starting point.

Answer 1

It is impossible to to come up with a sensible operational definition of "derogatory" for a study like this. As such, if there are studies like this, it makes sense to just dismiss them.

Example 1: I assume we can agree that a Republican calling Biden a "socialist" counts as a snarl word. At the same time, Sanders calling himself a socialist clearly doesn't count. Now if a Republican calls Sanders a socialist, it may or may not be intended to be derogatory.

Example 2: Consider the acronym "TERF" (Trans-exclusionary radical feminist). This is in itself just a descriptive phrase to describe people who use overall feminist rhetoric, but are very hostile towards trans women. I've often seen Terfs decrying the word "terf" to be a slur however. I suspect that what is happening here is that any word used to refer to a hated group has a good chance to be seen as derogatory.

Example 3: Is calling Trump a fascist using a snarl word? In many cases, yes, but often no. Basically, if using the phrase is eg based on a comparison of political movements such as Fascism proper, Austro-Fascism, Falange, National Socialism and Trumpism with rather dissimilar right-wing politics, it would just be the natural phrasing for a particular conclusion. On the other hand, if it is more based on "We hate Trump, we hate fascists, so let's call Trump a fascist", it is clearly a snarl world.

Example 4 (due to hszmv): For many slurs there are attempts to reclaim it by the groups referred to as such. Unless such an attempt is very successful, the standard is that members of the affected group using the phrase is not derogatory, whereas non-members doing so would be. This is reasonable clear-cut when considering a single utterance, but would be very cumbersome to scale up for a proper study. Since traditionally disadvantaged groups tend to heavily favour Democrats in the US, getting this wrong could skew the result a lot.

So to judge whether a particular utterance should count as a snarl world, one would need to take into account who makes that utterance for what purpose and in which context. And any such judgement is going to be too impacted by personal biases to be overly convincing.