The Fifth and Fourteenth Amendments to the Constitution each have a Due Process Clause. The Fifth Amendment Due Process Clause prohibited the federal government from depriving any person of “life, liberty, or property without due process of law.” The Fourteenth Amendment extended that prohibition to the states.

The Supreme Court has held that the Due Process Clauses ban government procedures the justices deem unfair. Thus the Court has said that the Due Process Clause of the Fourteenth Amendment requires states to allow an accused person to have a defense attorney, to allow an accused person to respond to accusations, and so forth. Legal scholars say that such cases are examples of “procedural due process.”

There is also a doctrine that goes by the oxymoronic name, “substantive due process.” The Court uses this doctrine to justify voiding any state or federal law the justices think has no possible “rational basis.” When the law infringes an interest the Court deems particularly important, it strikes down the law more readily. Understandably, the Court deems most of the rights protected by the Bill of Rights to be particularly important. The justices go further, however, and also void laws that “unduly” infringe interests not listed in the Constitution, such as abortion and sexual behavior.

In United States v. Windsor, for example, the Court relied (apparently -- the decision isn’t entirely clear) on the Fifth Amendment Due Process Clause to invalidate a federal law that provided that for federal (not state) purposes, “marriage” was limited to one man and one woman. In Obergefell v. Hodges, it held that the Fourteenth Amendment Due Process Clause invalidated similar state laws.

Is this what the Founders had in mind when they included “due process” in the Fifth Amendment in 1791?

No. Insofar as I am aware, there is not a shred of evidence that the Founders considered rights such as freedom of speech, legal counsel, etc. to be covered by the term “due process.” If they had, then they would not have listed them separately in the Bill of Rights. Nor, despite some claims to the contrary, did the Founders think “due process” included unenumerated rights. It is true that a few 18th century judges argued that laws that violated certain unenumerated rights were void, but those judges based their position on natural law, not on due process.

So what did the Founders’ Due Process Clause mean? It meant that in prosecuting a person criminally or civilly, the government must honor existing law. Government may not prejudice a defendant by changing the law retroactively. Government may not prejudice a defendant by making up the rules as it goes along.

The evidence for this conclusion is, in my view, simply overwhelming.

The phrase “due process of law” was a synonym for the phrase “law of the land,” which appeared in Chapter 39 of the 1215 version of Magna Carta, and was included in later versions as well. Chapter 39 read as follows:

No free person shall be seized or imprisoned, or stripped of his rights or possessions, or outlawed or exiled, or deprived of his standing in any way, nor will we proceed with force against him, or send others to do so, except by the lawful judgment of his equals or by the law of the land. (My translation).

If you read Chapter 39 carefully, you can see that it prohibited the king from punishing a person unless punishment was authorized by either (1) a judgment of that person’s equals (peers) or (2) a provision in existing law (”the law of the land”) that authorized the punishment. The latter of the two alternatives came to be called “due process of law.” Notice the disjunctive “or” -- a judgment by one’s peers was an alternative to due process, not (as the modern Court seems to think) part of it.* The drafters of Magna Carta inserted this language to rectify King John’s practice of manipulating or making up legal rules to hurt people he wished to attack.

The Founders knew this history well. It was discussed at some length in legal books of the time, including two by Matthew Hale, a highly regarded legal commentator.

The word “process” originally referred to the writ sent out by a court initiating a lawsuit (from the Latin procedere, to move foreword). We still use “process” in that way to refer to a legal summons, as in the phrase “process server.” Hale wrote that “no man shall be put to answer without presentment before justices or matter of record, or by due process and writ original according to the old law of the land.” Note the connection of “due process” with “writ original.” Note also that presentment, like the judgment of one’s peers, is an alternative to due process, not (as the modern Court seems to think) part of it.

As for the word “due:” I used to believe it was a flexible term meaning “reasonable.” However, the evidence has changed my mind. Contemporaneous dictionaries tell us the word “due” in this context meant “correct,” “right,” “proper,” or “appropriate.” In other words, due process was process “according to the old law of the land” -- that is, legally correct process.

On the other hand, the scope of due process, while constricted, was not quite as constricted as the foregoing might suggest. According to Giles Jacob’s legal dictionary (the favorite work of its kind among the founding generation), by the eighteenth century the word “process” could apply to judicial procedures generally. It was no longer limited to the initial court writ. The effect of this change was that the due process guarantee protected citizens at all stages of a suit, not just at the beginning.

In addition, the due process guarantee protected against executive as well as judicial misconduct. Recall that the guarantee arose as a check upon the executive actions of King John. Hale stated: “Regularly it is not lawful for any man to take away the life of another, though a great malefactor, without evident necessity, (whereof before) or without due process of law, for the deliberate, uncompelled extrajudicial killing of a person . . . is murder.” Obviously, if due process protected against extrajudicial killings, then it was not limited to court proceedings.

In England there was a theoretical reason for not applying due process protection against the legislature, for Parliament was considered all-powerful. But there was no such reason in the United States. In fact, as I point out in my book, The Original Constitution, the Fifth Amendment Due Process Clause may have been added to the Bill of Rights specifically to protect against Congress: John Lansing of New York and James Madison of Virginia probably sought its inclusion to guard against some federal retroactive legislation not banned by the Constitution’s guarantee against ex post facto laws.

In sum, the Fifth Amendment Due Process Clause was designed only to protect against prejudicial manipulation of legal rules against citizens prosecuted by the federal government. It was an important component of the Bill of Rights, but it was only a component. It was not a balloon that judges could blow to any size they wished.

What of the Fourteenth Amendment’s Due Process Clause -- the one that constricts state rather than federal power? The issue here is more difficult. Some researchers who concede that the Fifth Amendment Due Process Clause was narrow nevertheless maintain that by 1868 Americans had a broader understanding of “due process” than did the Founders. They would give the term different meanings according to where it appears in the Constitution. This is not as strange as it may seem: In a few other instances a term appearing in different parts of the document can have different meanings.

My initial review of the cases cited to show an expansion of due process between 1791 and 1868 found that all or nearly all fit within the earlier definition -- they were mostly responses to unfair retroactivity. However, I have not studied the question thoroughly, and therefore cannot offer an authoritative opinion on whether Fourteenth Amendment Due Process really is broader than Fifth Amendment Due Process.

* Some translations render the “or” as “and.” That is a mistranslation of the Latin conjunction vel.

Rob Natelson is Senior Fellow in Constitutional Jurisprudence at the Independence Institute in Denver. His constitutional studies are often cited at the Supreme Court by justices and parties.