11. The Ninth Amendment: A Hidden Key?

How an overlooked clause helped unlock modern constitutional rights

Every so often, a sleepy part of the Constitution suddenly finds itself in the spotlight.

That’s exactly what happened to the Ninth Amendment in 1965, when the Supreme Court struck down Connecticut’s ban on birth control for married couples in Griswold v. Connecticut.

Justice William O. Douglas’s majority opinion told us:

The Ninth Amendment provides: “The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.”

Earlier in the opinion, Douglas also wrote:

[S]pecific guarantees in the Bill of Rights have penumbras, formed by emanations from those guarantees that help give them life and substance.

Translation: There’s more to constitutional rights than what’s written down.

Wait — the Constitution protects rights that aren’t even listed? Now that’s intriguing. But what exactly does this open-ended clause mean — and how have scholars and judges tried to make sense of it?

That sounds pretty sweeping. But here’s the catch: can courts actually use it? Is it enforceable? Does it create new rights? Is it just a philosophical nudge?

Let’s dig in.

Five Models of the Ninth Amendment

Since the 1980s, scholars have offered five main theories about what the Ninth is actually doing. Some give it real legal power. Others see it as more of a polite constitutional reminder.

So when judges read this mysterious sentence, how exactly are they supposed to use it? Let’s walk through the options.

1. State Law Rights Model

This view says the Ninth protects rights already recognized in state law—rights in state constitutions or common law. It wasn’t meant to create new federal rights or give federal courts new powers. It was just there to make sure the new federal Constitution didn’t accidentally erase rights people already enjoyed at the state level.

In this model, the Ninth is a shield for state traditions, not a sword for new national rights.

2. Residual Rights Model

Now we’re in rule-of-construction territory. This model sees the Ninth as a way to block a bad argument: that listing some rights in the Bill of Rights somehow expanded federal power.

In other words, the Ninth is a constitutional reminder: “Just because we wrote some rights down doesn’t mean Congress gets new powers.” Less about protecting personal rights, more about keeping Congress in its lane.

3. Individual Natural Rights Model

Here’s where things get exciting—and the model that best matches how Douglas used the Ninth in Griswold.

The idea here is that the Ninth protects natural rights, i.e., rights that people had before government existed and still retain afterward. Rights like privacy, bodily autonomy, freedom to make intimate decisions.

Under this model, unenumerated rights are just as real (and just as protected) as the ones spelled out in the text. And courts should enforce them accordingly.

4. Collective Rights Model

Shift gears: this model focuses not on individual rights, but on collective political rights. Think of the people’s right to alter or abolish their government, or to exercise popular sovereignty.

In this reading, the Ninth protects “the people” acting collectively, not individual personal rights like privacy or autonomy. It’s more about political freedom than personal liberty.

5. Federalism Model

Finally, we have a version that fits neatly into federalism: the Ninth as a further safeguard against federal overreach.

Here, the Ninth serves as a check on how broadly courts interpret federal powers, especially implied powers under the Necessary & Proper Clause. By keeping federal powers narrow, the Ninth indirectly helps protect both state authority and individual liberty. But again, it doesn’t directly tell courts to enforce specific unenumerated rights.

The Ninth Amendment in Later Cases

Now for the twist: even after Griswold, the Ninth Amendment didn’t become the star of constitutional law.

Yes, the Court referenced it in later cases, but always as supporting background, not as the main tool for striking down laws.

• In Roe v. Wade (1973), Justice Blackmun mentioned the Ninth as one possible support for privacy rights, but grounded the decision mainly in the Fourteenth Amendment’s Due Process Clause.

• In Richmond Newspapers v. Virginia (1980), Chief Justice Burger referenced the Ninth in discussing the public’s right to attend criminal trials, again as part of the broader context of unenumerated rights.

But here’s the key point: the Court has never used the Ninth Amendment as the sole constitutional basis for recognizing a right or invalidating a law.

Why not? Because the Ninth isn’t like the First or Fourth Amendments. It doesn’t give courts a specific test or standard. It’s more of a guiding principle, a reminder that the Constitution’s list of rights isn’t exhaustive.

Think of the Ninth as the wise elder at the constitutional family dinner: always present, occasionally quoted, but rarely running the show.

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