The39thStep
Urban critical thinker
So on one hand they ‘just happened to have won’ or on the other hand they won because their opponents were divided ( worth exploring in itself as to why you think that was) and they ‘inherited’ the state army apparatus ( ie they had politically won over large sections of the army and navy) and had support in the soviets .The Bolsheviks were opposed on a mass scale. They just happened to have won. They were opposed by the Government which they overthrew, naturally, and also by supporters of the Tsarist regime, landowners, the Church etc. But also by many on the left. Some anarchists and Left Socialist Revolutionaries supported them at first, but later were purged or changed their minds. There were widespread revolts by Left SR's, Mensheviks, anarchists, 'Green' movements , Kronstadt rebels etc. The Bolsheviks inherited much of the apparatus of the state, including much of the army, so that gave them a great advantage. They were also very lucky. Their opponents were divided and weak.
Another thing which gets overlooked. Half the population were not ethnically Russian and became subjects of the Russian empire by conquest and subjugation. Most of them resented their Russian overlords, Tsarist or Bolshevik, in the same way that colonised peoples do the world over. Again, they were in no way any kind of coherent movement, nor could they be. That didn't stop widespread ethnic or religious anti-Bolshevik and anti-Russian activity for decades.
I’m not a great fan of how the revolution turned out but I think we need an honest appraisal as to why the Bolsheviks led the revolution and not the greens, anarchists , Mensheviks etc and why these forces were unable to pursue a second revolution .