Williamson v. Lee Optical

Due process of law, guaranteed by the Fifth and Fourteenth amendments to the U.S. Constitution, demands fairness for individuals in legal procedures applied by federal and state governments, respectively. Due process judicial deliberations involve both substantive and procedural dimensions. Whereas procedural due process looks at the manner in which individual rights are protected from governmental arbitrary actions such as right to an attorney or freedom from unreasonable search and seizure, substantive due process addresses the actual subject matter being regulated in a law or regulation, particularly personal rights or liberties.

By the 1990s, substantive due process court decisions had addressed most fundamental liberties expressly found in the first ten amendments as well as liberties not specifically described. Such unspoken liberties include the right to privacy in matters of personal choice--marriage, sexual concerns, parenthood, abortion, or "right to die" issues. The Supreme Court found the guarantee of these liberties embedded in various aspects of U.S. legal history including common law, moral philosophy, equal protection, and court precedents. The Court would sustain state or federal regulation restricting fundamental liberties only if the government could demonstrate a compelling reason in the public interest.