The interests of the people working inside a union might align with the interests of the workers they represent but as in any other organization they are focused on their own job and careers. The people at the bottom are probably more idealistic. When I hear about strikes in my country and their purpoted goals and the way they are made, most of the time I feel like their goal is to advance the careers of somebody in the union and not to get something for the workers. Furthermore most unions have clear links with some political parties, from left to right. They are part of the overall political play to the next elections.
Even the interests of the older members of the union diverge from the younger members (not unlike a country). Pretty much every defined benefit pension plan has “tiers” of benefits, where the older members voted themselves higher benefits in exchange for younger members getting less.
