I was watching some footage of Chomsky where he was talking about the October Revolution, and he brought up that, in his view, it was more of a coup than a revolution. He also brought up that the Bolsheviks were in fact a very vocal minority when compared to the other popular movements that were springing up in Russia at the time. What was the political climate like in immediate post-tsarist Russia?
The Bolsheviks had support from a key demographic: the workers in the Capital and a couple of major cities at the time. This is why they took power
Chomsky is basically correct that it was a coup. After the October Revolution Lenin actually held what was probably the last legitimate election in Russia until the 1990. And the Bolsheviks polled 23.5% of the vote (compare to 41% for the SR party of Kerensky).
http://en.wikipedia.org/wiki/Russian_Constituent_Assembly_election,_1917
Of course, they never tried that one again.