enforced by a local unit of government, such as a city.
The system of U.S. laws can be divided into four parts:
Constitution
Statutes
Regulations
Common law and case law
These four types of laws are described below in reference to the federal law. However, a similar system of laws occurs within the various states.
1.3.1 The Constitution17
The U.S. Constitution provides the framework for the U.S. legal system. The Constitution both empowers and limits government. The Constitution provides the supreme law of the land, and it is, by design, difficult to alter as a way of protecting long‐standing values.
The U.S. Constitution creates the federal government and divides the power into the three branches: legislative, executive, and judicial. The legislative power is vested in the U.S. Congress (Article I). (However, additional laws can be created by the executive and judicial branches.) The executive power is placed in the President (Article II). The judicial power is vested in the courts (Article III). This “separation of powers” was designed to create checks and balances to protect against tyrannical rule. Each of the three branches is considered separate but equal.
This caution over the concentration of power is a theme that runs throughout U.S. law. The Constitution, in addition to granting powers to government, also limits government’s powers and functions, particularly of the federal government. The first ten amendments of the Constitution are known as the Bill of Rights,18 and they protect individual rights by setting restrictions on the activities of the federal government.
1.3.2 Statutes
Within their power granted by the U.S. and state constitutions, respectively, Congress and state legislatures enact public acts, also called statutes. (Cities and other municipalities generally call their enactments of law “ordinances.”) All statutes must be consistent with the U.S. Constitution. State and local laws must also be consistent with the applicable state constitution.
1.3.3 Regulations
Although Congress and state legislatures have the primary authority to enact laws, they often delegate some of this authority to administrative agencies. This is particularly true for areas requiring technical expertise, such as health and science matters. The laws promulgated by administrative agencies are called regulations or administrative rules.
In theory, the administrative agencies merely execute the laws enacted by the legislature. However—because the legislatures often provide only a broad mandate—the agencies have considerable leeway in interpreting and applying their mandate. Typically, an administrative agency promulgates the detailed regulations that are necessary to translate the legislative mandate into operating standards. The regulations must fall under the scope of authority delegated by the legislature in statute. Regulations must also be consistent with other relevant constitutional and statutory requirements. Generally, regulations have the full force of law found in the enabling statute.
The executive branch agencies have increased in number, size, and importance since the 1930s. However, it is important to remember that the agencies can only carry out that which they are authorized to do by the legislature. In addition, the legislature determines the amount of funding the agencies receive. It is common for legislatures to enact popular statutes with noble sounding mandates but then fail to provide the necessary funds to agencies to carry out the new legislative mandate.
1.3.4 Case Law and Common Law
Both case law and common law are based on judicial decisions. Case law is the law established by the precedents of judicial decisions in cases (as distinguished from laws created by legislatures). Case law is important because of the tradition of following precedents. When a court addresses a legal dispute, it is usually guided by what has been decided previously in similar cases. These precedents become the case law. The general concept is that judges should follow the principles of law set down in prior decisions, unless it would violate justice or fair play to do so. Reliance on precedent serves to promote uniformity, predictability, and foster trust in a rule by law, not by person. Case law precedence is only set by the appellate courts.
Common law is the body of law based on legal tradition, custom, and general principles. Common law is embodied in case law and that serves as precedent or is applied to situations not covered by statute. U.S. common law was originally derived from English legal principles and traditions but now includes the precedents that have developed over time from the decisions of U.S. courts.
Common law generally applies only to areas of law where there is no statutory law. For example, if a firm discharges food‐processing waste on a field, and a foul smell permeates nearby homes, this may violate the common law of nuisance. Private nuisance common law might allow individuals to sue the processing plant. Public nuisance common law might allow a government official to take action. However, if a statute regulates acceptable waste‐handling methods for processing plants, then the legislative law can override the common law.
1.3.5 Federalism
To understand how the U.S. system of laws interrelates, one needs to understand federalism. The Constitution divides the power of government vertically between federal and state governments. Federalism is the term used to refer to this division of power. Federalism also limits the ability of a state to interfere or burden other states. An important example is that states cannot regulate or tax commerce in a way that places an undue burden on interstate commerce.
The Supremacy Clause of the Constitution provides that the Constitution and the federal laws are the supreme law of the land.19 This provision, as a general matter, means that the federal laws preempt state and local laws if they conflict.20 However, federal law can only preempt state law where there is authorization by the Constitution. The federal government only holds the powers delegated to it by the Constitution; other powers are reserved to the states or to the people.21
This division of power has been a great debate throughout U.S. history. However, the growth of national and international commerce and the problems of the modern age have led to a very expansive interpretation of the federal power. The Commerce Clause of the Constitution grants Congress plenary power to regulate commerce.22 Commerce covers a wide range of activities, not just direct interstate commerce, but any activities indirectly affecting interstate commerce. Today, given the nationally integrated economy of the United States, nearly all commerce is interstate or has an interstate impact; thus it is under federal purview.
However, states retain control over all matters not specifically delegated to the federal government.23 The key area here is that only the states possess the power to regulate specifically for the health and welfare of the people.24
