During my web-wanderings, I found this rather interesting nugget in Wikipedia (caveat lector, as always):
The iron law of oligarchy is a political theory, first developed by the German syndicalist sociologist Robert Michels in his 1911 book, Political Parties. It states that all forms of organization, regardless of how democratic or autocratic they may be at the start, will eventually and inevitably develop into oligarchies. […]
Michels stressed several factors that underlie the Iron Law of Oligarchy. Darcy K. Leach summarized them briefly as: “Bureaucracy happens. If bureaucracy happens, power rises. Power corrupts.”
Any large organization, Michels pointed out, is faced with problems of coordination that can be solved only by creating a bureaucracy. A bureaucracy, by design, is hierarchically organized to achieve efficiency—many decisions have to be made daily that cannot efficiently be made by large numbers of people. The effective functioning of an organization therefore requires the concentration of much power in the hands of a few. Those few, in turn—the oligarchy—will use all means necessary to preserve and further increase their power.
A close relative is Pournelle’s Iron Law of Bureaucracy (which is so spot-on that it hurts):
…in any bureaucratic organization there will be two kinds of people: those who work to further the actual goals of the organization, and those who work for the organization itself. Examples in education would be teachers who work and sacrifice to teach children, vs. union representative[s] who work to protect any teacher, including the most incompetent. The Iron Law states that in all cases, the second type of person will always gain control of the organization, and will always write the rules under which the organization functions.
I believe we are seeing both of these laws in action in the USA. The price of guarding a democracy against both these phenomena is eternal vigilance on the part of the governed.