I think what Eugine_Nier meant is that people who already have an interest in controlling other's ideas are morelikely to seek out office in an autocratic government, as opposed to autocracy having some magical corrupting nature that makes people want to engage in arbitrary censorship. This would pose a practical problem that hypothetical advocates of might or might not be able to resolve in a satisfactory way. I should note that the marriage between freedom of speach and democracy hasn't always been all sunshine and daisies: it took less than a decade after the ratification of the first amendment for the US to pass the sedition act.
I think what Eugine_Nier meant is that people who already have an interest in controlling other's ideas are morelikely to seek out office in an autocratic government,
Eugine_Nier should then communicate more clearly what he meant.
And this wouldn't explain why hereditary absolute monarchs that did NOT seek out office are also likely to censor and control speech.
as opposed to autocracy having some magical corrupting nature that makes people want to engage in arbitrary censorship.
Nothing magic here, I believe people wanting influence over other people...
Politics is the mind-killer; our opinions are largely formed on the basis of which tribes we want to affiliate with. What's more, when we first joined a tribe, we probably didn't properly vet the effects it would have on our cognition.
One illustration of this is the apparently contingent nature of actual political coalitions, and the prima facie plausibility of others. For example,
This suggests a de-biasing technique; inventing plausible alternative coalitions of ideas. When considering the counterfactual political argument, each side will have some red positions and some green positions, so hopefully your brain will be forced to evaluate it in a more rational manner.
Obviously, political issues are not all orthogonal; there is mutual information, and you don't want to ignore it. The idea isn't to decide your belief on every issue independently. If taxes on beer, cider and wine are a good idea, taxes on spirits are probably a good idea too. However, I think this is reflected in the "plausible coalitions" game; the most plausible reason I could think of for the political divide to fall between these is lobbying on behalf of distilleries, suggesting that these form a natural cluster in policy-space.
In case the idea can be more clearly grokked by examples, I'll post some in the comments.