Step one is to know that the model that is used to explain the U.S. political and economic systems and the behavior of the various participants could not generate the situation that exists today. Individual citizens are assumed to be independent minded and autonomous. Politicians are treated as giving civil minded individual who are drawn to a life of serving others. The government is defined as a Republic and assumed to operate in that capacity. A system with these two ingredients would not result in a system where all of the bills that are passed in congress are written by lobbyists. Bills would not be passed over the objections of constituents.
A model where both politicians and constituents are driven by instinct instead of reasoning in making decisions would produce the exact set of circumstances that are prevalent in the country today.
Where economics is concerned the acquisition of power is a standalone motivation, every bit as relevant as the profit motive in determining behavior. Economist routinely ignore the fact that laws of dominance and subservience are in effect 100% of the time. Anytime two or more individuals interact there is a subtle contest to determine which one is dominate. Countries fight wars for the same purpose.
The defined role of government is different than what governments do naturally. A country can be defined as a democracy or a republic but not come anywhere close to constituting self government. The natural function of government is to act as a means for folks to trade freedom for security. Government also serves as a way for an elite class to profit off of the activities of the general population. All governments do these two things. In the U.S. citizens are convinced that they are in charge of their government but for have very little influence over their leaders.
It is a popular notion that freedom is a gift from the creator and that it is universally appreciated. Neither is the case. There is nothing in religious writings, regardless of the version of the creator, that suggest people are born free. Simple observation demonstrates that people are free until they trade their freedom for something they deem more valuable.

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