One of the most well known and cherished of constitutional phrases (due process) appears in the Fifth Amendment: "nor [shall any person] be deprived of life, liberty, or property, without due process of law. . . ." It is repeated in the Fourteenth Amendment, this time as a specific restraint on State governments.
The phrase or its equivalent in English common law and some State constitutions, often expressed as "the law of the land," is derived from the Magna Carta. As they have evolved in the jurisprudence of the Fifth and Fourteenth Amendments, the due process clauses have come to stand for two independent protections: an assurance of procedural rationality, consistency, and integrity in any government action that could deprive a person of "life, liberty, or property"; and certain substantive rights not laid out explicitly in the Constitution but deemed essential to the principles of American democracy.
In its procedural meaning, "due process" does not turn entirely on the existence of rules laid out by legislatures or administrative agencies. It is instead an independent protection against the deprivation of rights established by the Constitution or by State or Federal law. It forbids capricious governmental actions. The Supreme Court has held, for example, that due process standards must be met in such varied contexts as the allocation of welfare payments, aspects of criminal trials not covered by more explicit provisions, the suspension or expulsion of children from public schools, and the dismissal of persons in the employment of state or federal government.
A conviction fails to comport with due process if the statute under which it is obtained fails to provide a person of ordinary intelligence fair notice of what is prohibited, or is so standardless that it authorizes or encourages seriously discriminatory enforcement.
As a source of substantive rights, the concept of "due process" has had a more checkered history. From the turn of the century into the 1930s it stood for a right to contract, and was used by the Supreme Court to negate many laws, such as laws aimed at occupational health and safety or conditions of employment. In more recent times it has been used, for example, to protect the liberty to educate one's children in a school of one's choice, to study a foreign language, to use contraceptives, and to travel across state lines.
The due process clause of the Fifth Amendment, moreover, is the source of the substantive protection against invidious discrimination by the federal government, a right explicitly protected by the Fourteenth Amendment against intrusion by the States.
Impact of technology
Technological change has affected both dimensions of due process. On the procedural side, for example, pretrial publicity facilitated by modem means of mass communications presents complexities in criminal trial procedures that were unknown when the due process clauses were added to the Constitution. In terms of substantive rights, science and technology have developed new ways of intruding on personal autonomy protected by due process.
The due process clause of the Fifth and Fourteenth Amendments, to some degree, may be construed to protect the "liberty" of persons in their privacy rights in cases that implicate "fundamental rights," or those "implicit in the concept of ordered liberty" such as marriage, procreation, contraception, family relationships, child rearing, and education.