I don't have much to discuss about the movement (although I am sceptical due to the repeated historical pattern of Mensheviks making way for Bolsheviks), but the subject we are discussing are democratic socialist countries, not movements, which as far as I am aware, don't exist. There are social democracies like Finland, which is what I assume the poster was referring to.
The whole modern democratic socialist movement as I understand it is primarily to fix exactly that issue.