It seems pretty clear to me that applying the definition I gave previously of “authoritarian violence” as “state-perpetrated violence against citizens with ideas the state finds threatening”, slavery could be considered “authoritarian violence” but “freeing the slaves” couldn’t.

What? How? The state did not order people to own slaves, and the slavers could free their slaves at will. It seems pretty clear to me that the opposite is true, that private citizens were operating in way that most reasonable people would call authoritarian, but by your definition cannot be called authoritarian because it’s only authoritarian when the state does it.

I suppose you could argue that the state failing to prevent individuals from performing authoritarian acts is a form of authoritarianism, but at that point the definition starts to break down. Is it possible for a state to be authoritarian through inaction? Suppose, for example, interracial relationships are technically legal, but every time one happens or is even suspected, a lynch mob strings someone up on a tree, and the government fails to prosecute.

If the state can be authoritarian through inaction, then at that point it becomes rather unclear what authoritarianism even means. You define it as, “state-perpetrated violence against citizens with ideas the state finds threatening.” But if those people pose a genuine threat to others, then doesn’t the state have an obligation to stop them in order to not be authoritarian, just as they do with the lynch mob in the previous example? And for that matter, isn’t it authoritarian for the US to allow Coca-Cola to fund death squads, in the original example?

I don’t think the term “authoritarian” defined in this way is useful or holds up under scrutiny.