With the slogan of social contract and natural human rights, Americans launched a wide-ranging struggle, won independence, broke away from British rule and established the United States of America. 1787 constitution "transforms natural law into constitution, and establishes American democracy and constitutional system". The system has the following notable features:

(A), "social contract" and "natural person's rights" principle

The idea of "social contract theory" emphasizes governing the country according to the constitution, the application and implementation of the principle of rule of law in political life, the people's right to establish a government, formulate and change the constitution and laws, and the fact that every citizen should abide by the constitution and laws as his sacred obligation. Constitution is a political contract between government power and civil rights, which is made for the purpose of public welfare with the consent of the ruled. Constitution is a contract law, the foundation of governing the country, and a sharp weapon to prevent the rule of man. Americans believe that the government is necessary, but it is necessary to prevent the government from abusing its power and officials from acting arbitrarily, from infringing on individual rights and from being ruled by men. It is under the provisions of this general plan of governing the country that the United States has completely constructed the model of a country ruled by law. All social relations between political parties, between political parties and governments, between governments and citizens, between citizens and enterprises and workers are mediated by the Constitution and laws.

(B), the decentralization of checks and balances mechanism

The idea and practice of restricting power are rooted in the profound insight into human nature. In order to prevent the weakness of human nature and enhance the good side of human beings, it is necessary to restrict and supervise the government and its officials. But the restriction itself is not all, and the spirit of decentralization and checks and balances lies in balance. The government structure must make all departments have proper control and checks and balances, so that power can effectively exercise its management functions for the purpose of public welfare and justice, while maintaining excellent control over power, realizing the balance between public power and people's power, and the dynamic balance between management and control, which is the destination of decentralization and restriction. Washington believes that balance and even the value of constitutional system is the theoretical basis of constitutional system.

The three power departments of the federal government are separated from each other and restrict each other. The president uses the veto to restrict Congress and the power to appoint judges to restrict federal courts. Congress uses the same power to restrict the appointment of federal court judges by approving and restricting officials appointed by the president, institutions established, treaties concluded with foreign countries and required budgets; The Supreme Court uses the power of judicial review to restrict the president's administrative decrees and congressional legislation, and if they are considered unconstitutional, declare them invalid. The two houses of Congress also restrict each other, and a bill must be passed by a majority of each house before it can be transmitted to the President for signature and approval. Military power is restricted by civil power. The president is the commander-in-chief of the national armed forces, and the mobilization and implementation of the army must be ordered by the president; Congress has the right to declare war, and the military needs are determined by Congress, each time not exceeding two years. The federal government and the state governments implement decentralization and mutual restraint. The main powers of the state, such as issuing currency, military affairs, diplomacy, commerce and foreign trade, are under the jurisdiction of the federal government, while the county and city local governments, state justice, industry and commerce, education, health and public security are under the jurisdiction of the state government. Exercise supervision independently within the scope of their respective authority. They use investigation to check whether the president and other actions violate the law or political discipline. The investigation was conducted in public, and the results were made public. If the circumstances of the violation are serious, they shall be impeached and dismissed from public office. The existence of a sound restriction and supervision mechanism makes state power independent of individual will, thus ensuring long-term social and political stability. Power is not interfered by power. As a representative body, Congress supervises the president and federal judges on behalf of the people. It uses investigation to check whether the president and other actions violate the law or political discipline. The investigation was conducted in public, and the results were made public. If the circumstances of the violation are serious, they shall be impeached and dismissed from public office. The existence of a sound restriction and supervision mechanism makes state power independent of individual will, thus ensuring long-term social and political stability.

(C), the principle of limited government

Theoretically speaking, the people are sovereigns, the power of the government comes from the people, and the people set up the government to protect their natural rights; It can be seen from practice that during the colonial period, the British king and his agents (governors) in American States abused their power. Therefore, when the United States wins independence and establishes a government, especially a strong government, it is necessary to grant power and limit power. The power of government is not absolute. It can only exercise the power entrusted to it by the people through the constitution, and cannot exercise the power that is forbidden to exercise. The government must not infringe on the people's rights.