Up voted. I will take your word and consider myself corrected for now, since the Russian Revolution is on my list of things to study in the future.

The quick and dirty assessment I used was "a regime that is formally a liberal parliamentary democracy becomes communism" when picking the example. I didn't however mean to imply it was just a guardian of negative rights, just that social democratic and socialist ideologies are strong attractors in democracies because they work like power pumps. This is why I called democracy early stage socialism. I'm farm from being alone in this view, many socialists basically think true democracy is socialism. The whole social democratic ideology was founded on this idea of step by step reforms towards socialism via democracy and that democracy will inevitably lead to it, so no need for violent revolution.