Fundamentals

Supremacy of Law: Meaning and Limits on Power

By Daniel Sardá · Published on September 07, 2026

7 min read1,528 words

Subjecting public power to law does not place ordinary legislation above the constitution. The distinction becomes clear when we ask who may decide, on what legal grounds, and subject to what checks.

The supremacy of law, understood as the requirement that power be subject to law, means that both those who govern and citizens are bound by legal rules, and that public authorities must not act arbitrarily. But the phrase raises a question: if law is “supreme,” where does the constitution fit in?

The answer requires distinguishing two issues. One concerns what limits those who govern; the other concerns the place each legal norm occupies within the legal system. Subjecting power to law does not mean that any enacted statute can override the constitution, or that its content is necessarily just.

Imagine that a community association applies for permission to hold a cultural event in a public square. The authority refuses permission without explaining which requirement the application fails to meet. Saying “the law allows me to decide” does not settle the matter: we still need to examine what that law permits and what limits apply to the decision.

What it means for power to be subject to law

Here, “supremacy of law” expresses a requirement of government: those who exercise authority must also be accountable under the law. Holding public office does not put anyone outside the rules that define the limits of their powers.

This idea forms part of the United Nations' institutional definition of the rule of law. That definition includes the state itself among those bound by law and calls for laws that are public, equally enforced, independently adjudicated, and consistent with human rights. It is a standard for assessing institutions, not a claim that every government meets it. See report S/2004/616, paragraph 6.

It also helps to understand “law” in a broad sense. A statute is, generally speaking, a law enacted by a legislature through the relevant procedure. Law in the broader sense encompasses a framework that also includes the constitution and other legal norms. Reducing it all to the legislature's will would obscure the very limits we are trying to explain.

“Supremacy of law,” the rule of law, and the idea of a state governed by law have closely related and overlapping uses. There is no universal terminology that separates them into distinct categories. To answer the opening question, the crucial distinction is whether we are discussing limits on power or the hierarchy of legal norms.

The constitution also limits lawmakers

Constitutional supremacy refers to the constitution's higher standing relative to lower legal norms in a system organized around that principle. Subjecting power to law raises a different, though related, question: what may each authority do, and within what limits?

A statute might, for example, give an administrative authority the power to authorize activities in public spaces. That legal authorization establishes who decides, but it does not give the authority unlimited power. Nor does it exempt the legislature from respecting the constitutional framework when setting the conditions for permission.

The Venice Commission distinguishes between the hierarchy of norms and the legal basis for public action in its updated Rule of Law Checklist, sections II.A.1–2. This distinction allows us to examine both the rule being applied and the legal powers of the body acting under it.

Two different problems could arise in our example: the authority might refuse permission for a reason the statute does not allow, or the statute itself might impose a restriction incompatible with the constitution. Both warrant scrutiny, but they will not necessarily be addressed through the same procedure or by the same body.

Key idea: Subjecting power to law includes placing limits on lawmakers. Ordinary legislation does not acquire unlimited authority simply because it has been enacted.

The mechanisms for reviewing these actions depend on the legal system. Constitutional supremacy alone does not mean that any judge can strike down any statute.

How to recognize an effective limit

The existence of a written rule is a starting point. To assess whether it actually limits an authority, we need to consider how people can learn what it requires, how it is applied, and how its use is reviewed.

The Venice Commission includes legal certainty, prevention of abuse of power, equality, and access to justice among its assessment criteria. Its overview of the checklist provides an institutional framework; it does not prescribe an identical legal remedy for every country.

In the public square example, predictability lets the association know which conditions it needs to consider before organizing the event. If the criteria emerge only after the application has been submitted, preparing the event becomes a gamble on what the authority will decide.

Equal application requires attention to relevant differences. Two events may receive different decisions because of factors such as capacity or scheduling conflicts, if the applicable rules allow those factors to be considered. The problem would be introducing personal preferences unrelated to those criteria. Equality does not mean deciding every application identically.

There must also be a way to challenge the decision before a body capable of examining it independently of the wishes of the person who made it. Judicial independence helps explain that safeguard. It does not ensure that the applicant will win or that a judge is infallible; it allows the decision to be assessed on its legal merits rather than simply upheld because an authority made it.

Enacting a law does not settle whether it is just

Suppose now that the refusal follows exactly what a statute provides. That answers part of the problem, but leaves other questions open: whether the statute meets higher legal requirements, and whether its content deserves a favorable moral or political judgment.

Debates about the rule of law distinguish conceptions focused on forms and procedures from those that incorporate substantive requirements, such as human rights. The scope of those requirements remains contested, as Kristen Rundle and Jeremy Waldron explain in “The Rule of Law,” sections 1 and 3.

The practical distinction is straightforward: enactment, legal validity, and justice are separate questions. Following a procedure for enacting a law does not resolve every question about its constitutional compatibility. In turn, judging a law unjust does not, by itself, establish that it is legally invalid.

Key idea: A moral criticism needs arguments about whether a law is just; a legal challenge needs to identify the legal limit that has allegedly been breached.

This distinction does not require us to accept unjust laws. It helps clarify what is being challenged and what change is sought. Calling for legislative reform, objecting to an abuse in the application of a law, and challenging a statute's constitutionality rest on different grounds.

Returning to the denied permit

To organize our analysis of the hypothetical case, we can begin with three questions:

• Who has the legal authority to decide? We need to identify the legal basis for that power.
• Which rule applies, and what does it allow the authority to consider? The reason for refusing permission must be connected to its criteria.
• Is that legal basis compatible with higher legal norms? The existence of a statute does not end the constitutional inquiry.

Next, the reasons for the decision matter. A response identifying a verifiable scheduling conflict makes it possible to question whether the conflict exists and whether it justifies the refusal. A response that merely says “it is not considered appropriate” leaves the criterion behind the decision unexplained.

This does not mean that every power to exercise judgment is arbitrary. Administrative authorities may need to assess circumstances that a rule does not describe exhaustively. The Venice Commission recognizes bounded discretion and examines reason-giving and accountability as safeguards against abuse in sections II.C.1–2 of its checklist.

In the example, assessing the conditions for using the square may fall within a legitimate legal power. Making permission depend on an official's personal preference, without any way to challenge it, removes that limit. The question is whether the judgment can be explained and reviewed under the applicable law.

Key idea: Having room to decide does not mean having permission to decide without reasons or checks.

Judicial review is one form of oversight. Its availability, scope, and possible effects must be examined in each jurisdiction; the example assumes neither a particular remedy nor a favorable outcome.

Planning your life without depending on a favor

From a classical liberal perspective, this limit matters because it protects room for personal choice against the changing wishes of those in authority. That is an editorial assessment of a principle also shared by other political traditions.

The association needs to know whether it can prepare its event under clear conditions and challenge a refusal based on faulty reasons. If everything depends on securing an official's goodwill, following the rules no longer provides sufficient guidance.

That is where the supremacy of law is put to the test: in the ability to demand a legal basis for an authority's decision and subject it to scrutiny. “Because I can decide” must give way to an explanation of why that decision falls within the authority's powers and respects the limits of the legal system.