Yes, a constitution can be changed, but the process is deliberately difficult

A constitution can be changed, but not the way a legislature changes a regular law. Most constitutions, including the U.S. Constitution, require a much higher threshold of agreement—usually a supermajority vote in the legislature, a public referendum, or both. The framers built this difficulty in on purpose: they wanted the basic rules of government to be stable, not shifting with every election cycle.

The specific process depends entirely on which constitution you are talking about. The United States Constitution requires a two-thirds vote in both the House and Senate to propose an amendment, then ratification by three-fourths of the state legislatures. Other countries use different thresholds. Some require a special constitutional convention. Some allow changes by referendum alone. Some require the sitting government to agree that change is necessary before the public even votes.

The key difference from ordinary lawmaking is that changing a constitution is meant to be rare and deliberate. A regular law can pass with a straightforward majority and be repealed the same way. A constitutional change is supposed to reflect a broad, sustained consensus that the basic structure of government needs to shift.

Key Takeaways

  • Constitutional changes require a higher vote threshold than regular laws—typically a supermajority in the legislature, a public referendum, or both.
  • The U.S. Constitution requires a two-thirds vote in Congress and ratification by three-fourths of state legislatures before an amendment takes effect.
  • Different countries set different thresholds; some require a constitutional convention, others allow referendums, and some require government approval before any change can be proposed.
  • The difficult process is intentional—constitutions are meant to be harder to change than ordinary laws so the basic rules of government remain stable.

How the U.S. Constitution amendment process works

An amendment to the U.S. Constitution begins with a proposal. Either two-thirds of the House of Representatives and two-thirds of the Senate must vote to propose it, or two-thirds of state legislatures must call for a constitutional convention to propose amendments. In practice, Congress has proposed all 27 amendments that have been ratified; no amendment has ever come through the state convention route.

Once Congress proposes an amendment, it goes to the states. Three-fourths of the state legislatures (currently 38 out of 50 states) must vote to ratify it. Some states can ratify, others can reject, and some can abstain—but 38 affirmative votes are required. If that threshold is reached, the amendment becomes part of the Constitution. If it is not reached within a reasonable timeframe (Congress sets the important date, usually seven years), the amendment dies.

This two-step process—proposal by supermajority in Congress, ratification by three-fourths of the states—means that a constitutional change cannot happen with just federal agreement or just state agreement. Both levels of government must broadly consent. The 22nd Amendment, which limited presidents to two terms, took four years to ratify. The 26th Amendment, which lowered the voting age to 18, took just over three months because public support was overwhelming.

Why constitutions are harder to change than laws

A regular law requires only a straightforward majority vote in the legislature and the signature of the chief executive. It can be passed in days and repealed just as quickly if a new majority takes power. A constitutional change, by contrast, requires sustained agreement across multiple branches and multiple levels of government, which means it cannot happen on a whim.

This design protects minority rights and prevents rapid swings in the basic structure of government. If the Constitution could be amended by a straightforward majority, the party in power could rewrite the rules whenever it won an election. Instead, an amendment requires either a supermajority (which forces compromise) or a referendum (which requires the public to directly consent). The difficulty is a feature, not a bug.

The downside is that constitutions can become outdated or fail to address new problems. The U.S. Constitution has been amended only 27 times in over 230 years. Some scholars argue this is a sign the process works as intended—the Constitution is stable. Others argue it means the Constitution cannot adapt to modern challenges. Both views are defensible; the trade-off is built into the system.

Different countries use different amendment thresholds

The United States is not the only country with a difficult amendment process, but the specific rules vary widely. Canada requires the approval of the federal Parliament and at least two-thirds of the provinces representing at least 50 percent of the population. Germany requires a two-thirds supermajority in both the Bundestag and the Bundesrat. France allows the President and Parliament to propose amendments, which then go to a referendum or to a joint session of Parliament.

Some countries make amendments easier. Ireland allows amendments by referendum alone, without requiring legislative approval first. Others make them harder. The Swiss Constitution can be amended by popular initiative (100,000 signatures) followed by a referendum, but the referendum must pass by a majority of both the people and the cantons—a double supermajority. Australia requires a referendum in which a majority of voters nationwide and a majority of states must both approve.

A few countries have made certain parts of their constitutions nearly impossible to change. The German Constitution declares that certain principles—human dignity, federalism, the separation of powers—cannot be amended at all, even by supermajority. This is called an "eternity clause." The idea is that some foundational commitments should be permanent.

What happens when a constitution is amended

Once an amendment is ratified, it becomes part of the Constitution with the same legal force as the original text. Courts interpret it the same way they interpret any other constitutional provision. The amendment does not replace the old text; it is added to it, and if there is a conflict, the newer amendment takes precedence.

The 21st Amendment is a famous example. It repealed the 18th Amendment, which had banned alcohol. Both amendments are still in the Constitution; the 21st straightforward overrode the 18th. Courts and legislatures then had to figure out what the 21st Amendment actually allowed—could states ban alcohol within their borders? Could the federal government regulate it? These questions took years to resolve through court cases and new laws.

An amendment can also clarify or expand rights, change the structure of government, or impose new limits on power. The 19th Amendment gave women the right to vote. The 22nd Amendment limited presidents to two terms. The 26th Amendment lowered the voting age. Each one changed the basic rules of how the government operates or who gets to participate in it.

When amendment proposals fail

Most proposed amendments never make it to ratification. Congress proposes amendments regularly, but only a fraction pass the two-thirds threshold in both chambers. Even fewer survive the ratification process. Since 1789, Congress has proposed over 11,000 amendments. Only 33 have been sent to the states, and only 27 have been ratified.

An amendment can fail at any stage. It might not get a two-thirds vote in Congress. It might pass Congress but fail to win ratification in enough states. It might win ratification in some states but not reach the three-fourths threshold before Congress's important date expires. The Child Labor Amendment, proposed in 1924, was ratified by only 28 states—far short of the 36 needed at that time. It technically remains pending, though it is no longer pursued.

Some proposed amendments have been rejected by the public in referendums. Australia has held 44 constitutional referendums since 1901; only 8 have passed. This shows that even when a government or legislature thinks a change is necessary, the public may disagree. The referendum requirement ensures that constitutional changes reflect broad public support, not just elite consensus.

Alternatives when amendment is too difficult

When the amendment process is too slow or too difficult, governments sometimes use other tools to change how the Constitution actually works. Courts can reinterpret constitutional language in light of new circumstances. Legislatures can pass laws that expand or limit constitutional rights within the bounds of what courts will allow. Executives can issue orders that test the limits of their constitutional power.

The U.S. Constitution does not mention the internet, social media, or digital privacy, yet courts have had to decide how the First and Fourth Amendments explore to these technologies. The Constitution does not explicitly authorize the federal government to regulate interstate commerce in detail, yet Congress has passed thousands of laws doing exactly that, with courts allowing it under a broad reading of the Commerce Clause. These are not amendments, but they are real changes in how the Constitution functions.

This flexibility is both a strength and a weakness. It allows the Constitution to adapt without going through the formal amendment process. But it also means that constitutional meaning can shift based on who is in power and how courts interpret the text. Some scholars argue this is why formal amendment is so rare—the Constitution changes through interpretation instead. Others argue this is a problem because it lets unelected judges rewrite the rules.

Frequently Asked Questions

How long does it take to amend a constitution?

In the United States, the timeline varies widely. Congress must first propose the amendment by a two-thirds vote, which can take months or years of debate. Once proposed, states have a important date (usually seven years) to ratify. Some amendments, like the 26th, ratified in 1971, took just over three months. Others, like the 22nd, took four years. The 27th Amendment, proposed in 1789, was not ratified until 1992—over 200 years later.

Can a constitution be amended to remove rights that already exist?

Yes, technically. The 18th Amendment banned alcohol, removing what many saw as a right to drink. The 21st Amendment later repealed it. However, amending to remove fundamental rights is extremely difficult because it requires a supermajority or broad public support. A modern attempt to remove voting rights or free speech protections would face enormous opposition and likely fail at ratification.

What if a state refuses to ratify an amendment?

That is fine. States do not all have to agree. An amendment needs three-fourths of states (currently 38 out of 50), so up to 12 states can vote against it or abstain and the amendment can still pass. However, once an amendment is ratified, it applies nationwide, including to states that voted against it.

Can an amendment be undone?

Yes, but only by another amendment. The 21st Amendment repealed the 18th Amendment, which is the only time one amendment has completely overturned another. Any other amendment would require the same two-thirds congressional vote and three-fourths state ratification to reverse.

Why has the U.S. Constitution only been amended 27 times in over 230 years?

The high threshold—two-thirds in Congress and three-fourths of states—makes amendment rare by design. This protects the Constitution from frequent changes based on temporary political majorities. However, courts have reinterpreted the Constitution many times to address new situations, so the document has changed in practice even without formal amendments.