Complex sentence: The revolutionaries, inspired by communist ideas, failed to take control as the Bolsheviks had in Russia, as the Social Democratic Party of Germany leadership refused to work with those who suported the Bolsheviks.
Split into simpler sentences: The revolutionaries, inspired by communist ideas, failed to take control as the Bolsheviks had in Russia. One reason was the resistance of the Social Democratic Party of Germany leadership and its refusal to work with those who suported the Bolsheviks.