> Those studies refute specific interpretations, in my mind comically over-specific ones.

That is the thing about science, of which Political science is definitely a science. Science engages with concrete and testable hypothesis. If a scientist wants to engage seriously with horseshoe theory then they have to have a concrete interpretation of it. Otherwise the scientist ends up being like Nostradamus and just put up intentionally vague predictions that will become true if you just interpret events exactly such that they line up with the vague prediction. And at that point, they are no longer a scientist, but a crook.

If horseshoe theory is stated in such a way that it becomes unfalsifiable then it is not a scientific theory. In which case it is still an unserious theory, worthy as only the meme that it is.

> Science engages with concrete and testable hypothesis

Sure. You raised mutual aid as a tactic. I shared examples of it being common in both camps.

> science, of which Political science is definitely a science

It can be. A lot of academic political science is not. The refutations on the Wikipedia are not really a refutation of the hypothesis in its strongest form, they’re akin to refuting evolution because your cat’s kittens still look like cats.

> If horseshoe theory is stated in such a way that it becomes unfalsifiable

It’s not. Political violence, conspiracy theorizing on social media and illiberalism around free speech are falsifiable claims.

Indeed. My point has always been that this theory is in fact falsifiable, and yet nobody has manage to come up with a convincing test results in the theory’s favor. This is enough for me to deem it unserious as an actual theory and relegate it to meme status.

As for shared tactics (e.g. mutual aid), the fact that occurrences exist is not enough to convince me (nor academia). Occurrences will exist of most tactics across the political spectrum. What you need is to tally the number of occurrences and show a statistically significant deviation between the center, but insignificant deviation between the far left and the far right.

If you want to be even more rigorous you would put severity weights on the occurrences. For example, blocking a weapons shipments to Israel by shutting down a port for 5 days would of high severity in the direct action category; but shouting slogans at a politician during a town hall would have low severity in the same category. Similarly conspiracy theorizing tends to be extremely common on the right (not even the far right; just the right) but it also exists on the left, and even the center (see e.g. Blue MAGA), however the pervasiveness of said conspiracy theories tends to be very limited on the left and on the center (less common * less severe), however on the right these conspiracy theories are extremely common and—equally importantly—pervasive (more common * more severe).

I‘m not gonna do this study, I don’t have the means nor the skills to do it. But somebody can. And until somebody does and shows convincing results, with a replicatable methodology, and independents teams replicates these results a couple of times, I will remain unconvinced that this theory is a serious theory with considering as anything more then a meme.

Anecdata: Bannon and Sanders speaking at the same event against data centers. Nonviolent, even. Illiberal? Maybe

Now I hear rumors of breaking "the" political firewall (ie, gap in horseshoe?) in France and Germany. Of reviving DDR style parties in East Germany that can work with AfD. Incoming data ..