Where do you think they learned their technique? I have a conservative friend who was a leader for the Longshoreman's Union and a personal friend of the late Harry Bridges. The Longshoreman & probably most union's leadership were and probably still are devotee's of Stalin.
Bridges asked my friend once if he liked the 40 hour work week, collective bargaining, etc.? My buddy said yes, and Bridges told him "Then you are a Marxist, too."