The Fifth and 14th Amendments of the U.S. Constitution contain clauses that the government cannot take away your “life, liberty or property without due process of law.” This language limits the ability of federal, state and local governments to pass and enforce laws, regulations, policies and rules unless they are fair and not arbitrary. There are two forms of due process: Substantive and procedural. Substantive due process looks at whom the law will impact and what impact the law will have. Procedural due process looks at how the law is implemented and enforced.
TL;DR (Too Long; Didn't Read)
Substantive due process requires the government to make sure that laws do not have an unfair impact on people, while procedural due process requires the government to follow fair procedures to ensure that the law applies equally to everyone.
Substantive Due Process
Substantive due process requires lawmakers to make sure that laws do not have an unfair impact on people. The courts apply different tests, depending on the nature of the law, to determine fairness. If the law will impact people because of their race or religion, or limits an important constitutional right such as freedom of speech or assembly, it is valid only if it promotes a compelling governmental interest. In contrast, when a law does not involve a constitutionally protected class such as race or religion, or impact important constitutional rights, the law only needs to be rationally related to a legitimate governmental interest. The lawmakers’ reasons for the enactment of a particular law must be based on facts and circumstances and not just an arbitrary preference.
Example of Substantive Due Process
A Nebraska state law that prohibited students from being taught in a foreign language in any private or public school, or from learning a foreign language prior to 9th grade, was ruled by the U.S. Supreme Court to violate substantive due process. The state of Nebraska tried to justify the law as helping students to learn English. However, the Court ruled that the law was not reasonably related to a legitimate governmental interest because parents have a liberty interest in directing the education of their children. Also, the Court said that there is no harm to the government in allowing students to learn a new language and that failing to teach a foreign language could result in some students not learning at all, which is contrary to the government’s interest.
Procedural Due Process
Procedural due process requires the government to implement and enforce laws by following fair procedures that apply equally to everyone. Some procedural protections are guaranteed by the U.S. Constitution, such as the Fifth Amendment protection from being forced to incriminate yourself, the right to a speedy trial and freedom from prosecution for the same crime twice, known as double jeopardy. Procedural protections play a large role in all areas of criminal law enforcement, from arrest to punishment. In civil law, procedural due process limits the government's actions when taking or limiting your land or personal property, government entitlements such as Social Security, and government-controlled benefits such as driver’s licenses. Governments cannot take these actions without giving you a chance to object or be heard. How much process is due depends on the extent of the deprivation weighed against the importance to the general public.
Example of Procedural Due Process
City health inspectors were found by the Supreme Court to satisfy due process when they made a surprise visit, pursuant to a city law, to a Chicago cold storage facility and seized 400 pounds of spoiled chicken meat. The business owner said that he was denied due process because he was entitled to a hearing before the meat could be seized. The Court disagreed, saying that no hearing was needed because the business was on notice that they could not store spoiled meat and if they did, it was subject to immediate seizure. The Court also said that the city had a legitimate interest in protecting the health of its citizens.