1. Constitutional Law
The law as expressed in the U.S. Constitution and the various state constitutions. The U.S. Constitution is the supreme law of the land. State constitutions are supreme within state borders to the extent that they do not violate the U.S. Constitution or a federal law.
2. Statutory Law
Laws or ordinances created by federal, state, and local legislatures and governing bodies. None of these laws can violate the U.S. Constitution or the relevant state constitutions. Uniform laws, when adopted by a state legislature, become statutory law in that state.
3. Administrative Law
The rules, orders, and decisions of federal or state government administrative agencies. Federal administrative agencies are created by enabling legislation enacted by the U.S. Congress. Agency functions include rulemaking, investigation and enforcement, and adjudication.
4. Case Law and Common Law Doctrines
Judge-made law, including interpretations of constitutional provisions, of statutes enacted by legislatures, and of regulations created by administrative agencies. The common law—the doctrines and principles embodied in case law—governs all areas not covered by statutory law or administrative law.
The U.S. Constitution established a federal form of government, in which government powers are shared by the national government and the state governments. At the national level, government powers are divided among the legislative, executive, and judicial branches.
1. The Commerce Clause
The commerce clause expressly permits Congress to regulate commerce. Over time, courts expansively interpreted this clause, thereby enabling the national government to wield extensive powers over the economic life of the nation.
A. Today, the commerce power authorizes the national government, at least theoretically, to regulate almost every commercial enterprise in the United States. In recent years, the Supreme Court has reined in somewhat the national government's regulatory powers under the commerce clause.
B. The Tenth Amendment reserves to the states all powers not expressly delegated to the national government. Under their police powers, state governments may regulate private activities in order to protect or promote the public order, health, safety, morals, and general welfare.
C. If state regulations substantially interfere with interstate commerce, they will be held to violate the "dormant commerce" clause of the U.S. Constitution. The positive aspect of the commerce clause, which gives the national government the exclusive authority to regulate interstate commerce, implies a "dormant" aspect—that the states do not have this power.
2. The Supremacy Clause
The U.S. Constitution provides that the Constitution, laws, and treaties of the United States are "the supreme Law of the Land." Whenever a state law directly conflicts with a federal law, the state law is rendered invalid.
The Bill of Rights, which consists of the first ten amendments to the U.S. Constitution, was adopted in 1791 and embodies a series of protections for individuals—and, in some instances, business entities—against various types of interference by the federal government. Today, most of the protections apply against state governments as well.
1. Freedom of speech
Under the First Amendment, speech, including symbolic speech, is given the fullest possible protection by the courts. Corporate political speech and commercial speech also receive substantial protection under the First Amendment. Certain types of speech, such as defamatory speech and lewd or obscene speech, are not protected under the First Amendment. Government attempts to regulate unprotected forms of speech in the online environment have, to date, met with numerous challenges.
2. Freedom of religion
Under the First Amendment, the government may neither establish any religion (the establishment clause) nor prohibit the free exercise of religion (the free exercise clause).
3. Due process
Both the Fifth and the Fourteenth Amendments provide that no person shall be deprived of "life, liberty, or property, without due process of law." Procedural due process requires that any government decision to take life, liberty, or property must be made fairly, using fair procedures. Substantive due process focuses on the content of legislation. Generally, a law that limits a fundamental right violates substantive due process unless the law promotes a compelling state interest, such as public safety.
4. Equal protection
Under the Fourteenth Amendment, a law or action that limits the liberty of some persons but not others may violate the equal protection clause. Such a law may be upheld, however, if there is a rational basis for the discriminatory treatment of a given group or if the law substantially relates to an important government objective.