Americans keep referring to democrats as ‘left’, but truth be told, there is no left in american politics, at least none of any significance.
What you guys have is a political scenery consisting of right-wing and ‘righter-wing’. In Europe, both of the US parties would have had to be merged into one, given the non-existent difference between them. Sure, they differ in their standpoints on specific political issues but the difference between two democratic (or conservative) administrations are about as big as the between any two administrations. The Soviets, for all their very significant fault, at least had the honesty to admit to having a one-party political system.