The Iron Law of Oligarchy is an idea in sociology that suggests all democratic organisations eventually turn into oligarchies. Developed by Syndicalist Robert Michels and is often used as one of the strongest arguments against democracy, especially representative democracy.
Evidence
Political Parties
Two of the most well studied examples include the German Social Democratic Party and the German Green Party.
Trade Unions
Student Unions
Wikipedia
One study in 2016 of he evolution of Wikipedia's network of norms over time found that it is consistent with the iron law of oligarchy. Their quantitative analysis is based on data-mining over a decade of article and user information. It shows the emergence of an oligarchy derived from competencies in five significant "clusters": administration, article quality, collaboration, formatting, and content policy. The study noted, "The encyclopedia’s core norms address universal principles, such as neutrality, verifiability, civility, and consensus. The ambiguity and interpretability of these abstract concepts may drive them to decouple from each other over time."[1] This view conflicts with the view proposed by some that Wikipedia is democratic and self-improving, but the lack of formal hierarchies in Wikipedia and commitment to certain ideals prevent a fixed hierarchy and keeps Wikipedia open-source.
Breaking the Law
It is possible to break the law and preserve democratic institutions