Are you sure? I'd love to see credible sources for this data, for the US. Note that sources talking about "hate crimes" are unfortunately not usable here simply because they by definition exclude violence towards groups that violent left-wing groups target. I am aware that after this last election there was an upsurge in hate crimes; there was also an upsurge in violent attacks on Trump supporters. I have had little luck finding good numbers on what's going on, and would appreciate pointers.
Also, are we talking about recent history, or historically? Because again, for the US, there was a good deal of left-wing violence in the 70s that has been successfully whitewashed out of history. For example, some (but not all) of the leaders of https://en.wikipedia.org/wiki/Weather_Underground moved right on to positions like "Clinical Associate Professor of Law at the Children and Family Justice Center at Northwestern University School of Law" and "communications director at Environmental Advocates of New York" (and for the same one, "heads up his own consulting firm called Jeff Jones Strategies that specializes in media expertise, writing, and campaign strategies that help grassroots and progressive groups achieve their goals"). Going further down the list we have people becoming high school teachers and then academics specializing in education, and mathematics instructors .
At least as of 20 years ago, none of this was discussed in high school history classes that cover the period. Most people who didn't personally live through it aren't aware that any of this ever happened.
> or even centre-right authoritarians as if they were opposites
The centre-right authoritarians, by that definition, are not the ones involved in what would be considered "leftist violence" in the US.
Sure, there was an uptick in attacks on Trump supporters. But you take all of those and I'll take only violence against muslims or trans people, your choice. Hell, if I took only violence against non-muslim brown people mistaken for muslims the numbers would still be higher.
Do you have a source for that? Because, again, I've had a _very_ hard time finding credible numbers for this stuff, and would love some actual data.