This entire discussion is about semantics, so I see no issue with getting fiddly with it.
My point is you are redefining words as you go, which is pointless.
for authoritarianism being illiberal, I don’t see how that is tautological
Because you have defined it tautologically.
Authoritarianism is when the government or ruler has absolute control and has no obligation to accept input from the populace over which they rule
Which doesn't apply to any of these 'far left extremist' projects you're talking about.
And yes, I do think there has never been a truly liberal society, just as there has never been a truly communist society or any other -ist or -ism based society. They are concepts we can strive for, but adhering perfectly to the academic definition of any of these concepts is not realistic. I think the USA is fundemantally illiberal in many regards, and we would do well to strive to correct those aspects.
Then how can you say you are anything but a leftwing extremist yourself?
As for the definitions of those specific aspects of liberalism, yes, of course it is those aspects defined under the framework of liberalism. It would just take thousands of words to provide the entire context and it’s not super important here.
It's extremely important; it's essentially you saying "It's not authoritarianism when we do it!"
When I’m talking about the extremist sides of the spectrum, far left and far right, I am referring to those who tread into territory where their ideology becomes ostensibly dangerous. The most common version of this is directly supporting things like oppressive authoritarian rulers and population cleansing, There are absolutely people on both the left and the right who would see those as acceptable means to their end of implementing their preferred ideology. Right wingers who want to ethnically cleanse populations they see as problematic or inferior are no better than the far leftists who want to guillotine whoever they decide is the bourgeois.
And this is the crux of my point; you say this like the center of the spectrum, and liberals, aren't dangerous; aren't perfectly happy to support authoritarian rulers and populations cleansing, who see genocidal violence acceptable means to their ends of maintaining their preferred ideology. In fact, in our current world, the overwhelming majority of violence and suffering is caused by moderates and liberals. You need to examine your blind spot here, and stop acting like the moderate position is somehow pacifism.
And yes, I actually do have a lot of issues with the French and American revolutions, and I do not think Churchill was a particularly good guy.
So no, you don't hold liberals to the same standard you hold leftists, you instead hold a massive, systematic double standard.
I don’t think they are the same as the Russian and Chinese revolutions.
And there it is, right here, the deep seated double standard. Like I said; you don't hate authoritarianism, you hate political heterodoxy.
but the Chinese and Russian versions resulted in higher death tolls and much more unhealthy systems coming out the other side (in my subjective opinion).
Death tolls are not subject to "subjective opinions"; you're just wrong
Which one of those guys is worse depends on your subjective values, but for me, I’d say Lenin is the worse guy.
And that says a fuckload about how fucking evil your subjective values are.
See, this is why I loath liberals, in some ways more than fascists; at least fascists are open about their evil. You don't actually hold principles you apply consistently, you don't actually believe in all that shit about autonomy and liberty. They're all just a smoke screen to justify ruthlessly crushing any oppositions: martial law, torture, murder, genocide, chattel slavery; these are all perfectly forgivable in defense of liberalism, at worst they'll get you called "not a great guy", but you certainly won't be called "a dangerous authoritarian in crazy land" and you will always, always, be certain that you will be considered better than any leftist leader.
I seriously cannot get over saying chattel slavery and genocide are better than Lenin, or that Churchhill; a man who genocided millions of people and proudly presided over the most brutal empire in history, is better than the Russian revolution.