How were the Bolsheviks and later Soviet Russia able to keep control over the Russian people, while the Romanov's were not. Weren't they both autocracies in their own way?
I'm a bit confused by your question. Neither the Bolsheviks nor the Romanovs were able to keep control in the end but the Romanovs ruled for over 300 years. Much longer than the Bolsheviks did. Can you clarify a bit what you mean?