The Supreme Court’s recent 8-1 decision in Heien v. North Carolina sadly turns the old slight “close enough for government work” into Fourth Amendment jurisprudence.

Americans have good reason to fear and loathe this latest creative interpretation of the Fourth Amendment because it weakens the rule of law over government.

A North Carolina police officer pulled over Nicholas Heien because one of his car’s brake lights was out. The state’s law requires only one light to be working, so the stop was based on a mistake of law.

After Heien was pulled over, he gave consent for the officer to search his car. The officer found cocaine in the car, then placed Heien under arrest.

Heien later claimed the initial stop was not legal under the Fourth Amendment of the U.S. Constitution. The Supreme Court ruled that the mistake for the initial stop, which was a seizure under the Fourth Amendment, was reasonable and therefore lawful.

The Fourth Amendment’s economy of words belies its breadth, complexity and history vis-a-vis tyranny. The saying “Every man’s home is his castle” is found in the common law that leads up to the amendment.

The Fourth Amendment protects our most personal property and our most intimate rights. It is a protection for every aspect of our lives including phone calls, emails, our work product, our very bodies.

It is a protection of liberty, property, even life — since stops or searches by our militarized government sometimes turn violent. It is a legal control on government preceding the sacrosanct right of due process.

The Fourth Amendment is intended as a hedge against totalitarian acts by government. Cracks in the amendment’s foundation and misapplication by its enforcers are the basis of a police state, so it’s not a law for which the judiciary should be generous in the government’s favor.

Timing of the Heien decision is especially bad. Record numbers of Americans fear their government, according to Gallup polling. There are unprecedented criminal ramifications for civil functions, which the Heritage Foundation has dubbed “overcriminalization.” Our government spies on us and uses military force in police actions.

Each day, millions of innocent Americans face Fourth Amendment scenarios. Victims of abusive government searches and seizures range from a pig farm raided by the state of Michigan over grazing practices to swanky corporations such as Microsoft, which was joined recently by Verizon, Apple, Amazon, AT&T and eBay in its fight against Justice Department attempts to seize overseas emails.

Chief Justice John Roberts’ creative and harmful majority opinion in Heien claims precedent, writing that the “ultimate touchstone of the Fourth Amendment is ‘reasonableness.’ ”

Repeating such lines often enough in case law sometimes gives fluff the appearance of substantive and controlling law. But it is inherently unreasonable that mistakes of law may make lawful what should be unlawful.

Roberts also relies on early American case law about personal liability of federal inspectors and tax collectors. There was a time when federal search and seizure officials could be sued for trespass. That is a practice that should be brought back, but Roberts, joined by the court’s originalists, misapplies those cases to create a new Fourth Amendment interpretation that weakens the rule of law over government.

Lone dissenter Justice Sonia Sotomayor grasps what is at stake when she writes, “The meaning of the law is not probabilistic in the same way that factual determinations are. Rather, ‘the notion that the law is definite and knowable’ sits at the foundation of our legal system. ... Departing from this tradition means further eroding the Fourth Amendment’s protection of civil liberties in a context where that protection has already been worn down.”

The term “probable cause” found in the Fourth Amendment means that there is an objective suspicion that a law has been or is about to be broken. The amendment is designed to prevent the government from doing what is unlawful without probable cause. The ultimate touchstone of the Fourth Amendment, therefore, should be the laws being enforced.

The decision in Heien lowered the bar of expectations for all sorts of government searches and seizures, and that cannot be reasonable under the Fourth Amendment.

Mark J. Fitzgibbons is co-author with Richard Viguerie of The Law That Governs Government. Thinking of submitting an op-ed to the Washington Examiner? Be sure to read our guidelines on submissions for editorials, available at this link.