I'm thinking each "group" is maybe two or three people with a phone and a website. It's only the media that makes these leftist special interest groups seem like some kind of massive "movement."
Like in ‘The Life of Brian’ Monty Python film where the leader of a small group says “We’re the Peoples Front of Judea!” and one of the group says “I thought we were the Popular Front?” and the leader says “No, that’s him over there.” and someone else yells “Splitter!” at the lone “Popular Front” splinter group member. :)