North Korea and the Soviet Union don't qualify as democracies...

None of those examples are democracies, just greater pursuit of communism which is what the protestors wanted

The point I was aiming at was that the benefits of democracy outweigh the blights of communism over the long term. You can argue whether or not that is the case, but North Korea and the USSR aren't examples to the contrary.

Are there any examples that support your thoughts? A transition out of authoritarian single party communist rule to democratic [single or multi party] communist rule?

An example to support my thought would be a communist democracies becoming more capitalist over time. Unfortunately I believe communist regimes have been predominantly authoritarian, so I don't have any good examples. I believe there aren't any good counter examples either tho, so it's anyone's guess.