The Bolsheviks seized power from the reformists, if the American left abandons electoralism for doomsday prepping than when the crisis hits it'll be the fascists in charge, the equivalent of the White Army already installed in Moscow, that's not a recipe for a Soviet Union, that's how you end up with Indonesia 1965
For the socdems to fail and hand the socialists the golden ticket, the reformists first have to be in government