Prior to the communist revolution that produced the Union of Soviet Socialist Republics (USSR), the old Russian empire had already been a place where heavy authority rested in the hands of an autocratic ruler. The history of control by the tsars was one factor that made the USSR susceptible to a totalitarian style government.
Another factor was the social and economic backwardness of the country. In trying to modernize and industrialize the nation, first Lenin and then even more strongly Stalin took control of measures to propel the economy forward.
The death of Lenin was a factor too, in that there was some struggle over leadership following his death. Stalin used a repressive, totalitarian approach in order to solidify his own hold on power.
Finally, the idealistic vision of creating the world's first communist society created a situation where leaders would push propaganda to that end and people were convinced to believe it. The more unrealizable the goals of the country were, the more a totalitarian state was needed to keep the project going in the direction of its stated agenda.
