The United States is a republic. The powers, limitations, and organization of the government are set forth in a written constitution. The U.S. Constitution is a model for governments around the world and a major source of law in the American legal system.

The Constitution is based on the principle of federalism — the division of the duties and responsibilities of government between a national, or federal, government and the governments of each individual state. Following the principle of federalism, the Constitution grants the federal government certain enumerated powers.

All other powers not specifically delegated to the federal government are reserved by the states. This allocation of the powers of government is sometimes referred to as “state's rights.” The allocation of the powers of government also has a significant effect on the operation of law in the United States.

The Federal Constitution

The language of the U.S. Constitution is generally sweeping and vague. The drafters of the Constitution wanted a document that would allow for inevitable changes in social attitudes toward government and the law and economic changes that might influence the direction of the law. In spite of its broad language, however, the Constitution establishes the fundamental principles on which the American legal system is based.

The Constitution is the supreme law of the land. This means that no other source of law may conflict with its provisions. A federal or state statute that conflicts with the Constitution is invalid and cannot be enforced. A judicial decision that fails to follow the Constitution is not effective. The final interpretation of the meaning of the Constitution rests in the hands of the United States Supreme Court.

The principle of federalism and the supremacy clause of the Constitution affect the development of law in three ways:

• The exercise of individual rights. The Bill of Rights guarantees each individual citizen certain rights. Because the rights of freedom of speech and assembly, freedom from unreasonable searches and seizures, the privilege against self-incrimination, and the right to a jury trial are included in the Constitution, they cannot be limited or abrogated by the states.

  The Constitution also grants individuals the right to due process when a fundamental right is affected and to have the equal protection of the laws. State and local laws may not deprive any citizen of the rights guaranteed by the Bill of Rights.

• The relationship between the federal government and state governments. The Constitution grants certain powers to the federal government. In some cases, the powers of the federal government may not be exercised by the states, such as the power to negotiate treaties with foreign governments. In other cases, the states may exercise a specific power, but only if the federal government has not acted.

  When there is federal legislation, the states are precluded from enacting any legislation on the subject. On the other hand, where the federal government has not acted, the states are free to choose their own approach.

• The relationships between states. To minimize the conflicts created by separate state legal systems, the Constitution requires each state to give “full faith and credit” to the legal decisions of another state. Thus, a litigant who obtains a verdict in one state may collect on the verdict in another state, even if there is a difference in legal theory between the states.

State Constitutions

Each state has its own constitution. Most of them follow the structure of the U.S. Constitution, while reflecting individual variation in the form of state government. For example, all the states but one follow the federal model of a two-house legislature; only Nebraska follows the unicameral legislative model.

There are also variations in state judicial systems that are quite significant. Judges are appointed in some states; in others, judges are elected. No state allows its judges to serve for life as in the federal system.