This post is a response to the question posted by 
What are some historical examples of planners who created power and became totalitarian leaders?
The classic historical example of totalitarianism is the Soviet Union in the 20th century. It is an especially good example since so many people still remember later forms of the USSR and its mark is still left in modern Russia and other former Soviet states. The Soviet brand of totalitarianism is notable because it was originally based on socialist ideas but got stuck on totalitarianism and we all know how well that turned out. It is unique in that the ideas that Soviet totalitarianism was based on were based on someone else's ideas. Karl Marx was not Russian and did not write his books with Russia in mind. The Russians who eventually created the Soviet Union saw an opportunity in Marx's works to gain power for themselves and the Russian people would go along with it.
The popularity of Marxism in Russia made it possible for a few people to capitalize and consolidate power. Lenin and the socialist party came to power and created the Soviet Union and Ironically paved the way for Stalin to take power from them and keep it all to himself. The rise of the Soviet Union showed how dangerous the road to socialism is. No civilization has ever tried to get to socialism and made it all the way there. They always get stuck in one of the intermediate steps where the power falls to a few people. The Soviet Union is a great example. It also shows how hard totalitarianism is on the people. The working class build the society and sets it up, and then is "sold out" for the gain of the oligarchs. Finally, it showed how difficult it is to wrest power from a totalitarian system. Once Russia committed to communism, power quickly centralized and it took decades of oppression and starvation for it to fall, and the argument can be made that parts of the old regime still survive.