Separation of Powers Under the U.S. Constitution
By Samuel Strom, J.D. | Legally reviewed by Edward Maggio, Esq. | Last reviewed November 07, 2024
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The Framers of the U.S. Constitution divided the federal government's powers between three separate branches of government. This structure, they hoped, would prevent tyranny from a single branch, lead to an effective government, and preserve the liberty of U.S. citizens.
Separation of powers is one of the most well-known legal and political doctrines in constitutional law. The Founders devised this solution to avoid what they viewed as the tyranny of the British government.
The United States Constitution's structure answers the question of "who" exercises the power to govern. This separation of powers doctrine (along with federalism — which answers "how" power is divided) was important to the colonists. After all, the American colonists had just won a war against the British and their powerful central government. The structure they devised created a federal government that could govern the country effectively. At the same time, it ensured the liberty of the governed.
This article provides historical background about how and why the Framers structured the Constitution, with an emphasis on the doctrine of separation of powers. It then describes each branch of government, including its powers and abilities to check the other branches.
Why Do We Have a Separation of Powers?
The three branches of the U.S. government each have separate powers. This allows one branch to perform its tasks efficiently and effectively. However, it also allows each branch to "check" the other two branches' actions. Therefore, although their powers are separate, they often overlap with the other branches.
The separation of powers doctrine protects the life, liberty, and pursuit of happiness promised to citizens. It is also the key to the U.S. government and a reason why so many countries have based their constitutions on the U.S. Constitution. No single branch of government has all the political power, nor does one have absolute power over the others. Instead, the Constitution sits as the supreme law of the land, and each branch must adhere to it.
To understand why the United States of America designed its government with a unique separation of powers doctrine, it helps to understand the principles underlying the colonists' decision to declare independence.
The Declaration of Independence
At its core, the Declaration of Independence stands for the idea that the people should be free to govern themselves and protect their natural rights. The colonists relied on this principle because, for years, the British monarchy had ruled over them without giving them a say in governance. Political tensions arising over taxation without representation ultimately led to the Revolutionary War and the signing of the Declaration of Independence.
The Declaration of Independence, signed July 4, 1776, states the following:
"We hold these truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, & the Pursuit of Happiness—that to secure these Rights, Governments are instituted among Men, deriving their just Power from the Consent of the Governed, that whenever any Form of Government becomes destructive of those Ends, it is the Right of the People to alter or abolish it, and to institute new Government, laying its Foundation on such Principles, and organizing its Powers in such Form, as to them shall seem most likely to effect their Safety and Happiness."
In the 11 years between declaring independence and the proposal of the U.S. Constitution, America struggled to govern itself. It did not resemble a unified country. Instead, it more closely resembled a military alliance between 13 separate countries. There was some cooperation, as they each sent delegates to a Congress to discuss and debate common purposes and issues. However, Congress itself had little power to enforce rules.
The Second Continental Congress drafted the Articles of Confederation in 1777, hoping to unify the 13 colonies. However, due to the ongoing war and disputes between colonies, the states did not ratify it until 1781.
In practice, instead of creating the "United States," it's more accurate to say it created a treaty between the states. Article III of the Articles created a "league of friendship," in which each state government had sovereignty, but the federal government had little power at all.
Soon after defeating the British in 1783, America faced another threat—itself. It managed to win the war but faced internal conflicts between the states. Among other issues, individual states placed tariffs on goods traded by other states. Each state had its own constitution, and some refused to apply their laws to citizens from other states.
A weak federal government had little in the way of authority to unite the states, with some openly defying Congress' decisions. Additionally, the Articles did not allow amendments unless every state agreed to them.
Before long, these disputes between the states threatened to destroy the new country. The country's economy also suffered in the years after the American Revolution. Early America was a political mess, and Americans knew change was needed.
The Constitutional Convention
In 1787, Congress called a convention of delegates from each state to amend the Articles of Confederation. Congress instructed the delegates to suggest changes to the existing government during the Constitutional Convention. Instead, they quickly began creating an entirely new form of government. In essence, they plotted another political revolution — this time, over their own government.
The delegates at the Constitutional Convention (the "Framers") included some of the most influential figures in American history. George Washington presided as president. Alexander Hamilton convinced Congress to call for the Convention in the first place. James Madison, known as the "Father of the Constitution," convinced skeptical delegates to attend the Convention, including Washington. He also drafted the Constitution and persuaded the Convention to accept it. Other Framers included the following:
Benjamin Franklin
James Wilson
Gouverneur Morris
George Mason
In short, the Framers comprised an all-star team of 55 political figures from the original 13 colonies.
Relying on the principles stated in the Declaration of Independence, the Framers adopted the U.S. Constitution after debating what their new country's government would look like in the summer of 1787. The Constitution's Preamble echos the Declaration of Independence by stating the following:
"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution of the United States."
The Constitution's structure reflected the Framers' intent to create a strong national government. They borrowed ideas from ancient and existing governments and embraced different theories of political science to craft a new government.
James Madison, for example, borrowed ideas from Montesquieu, a French noble and scholar who advocated for a separation of powers structure. In doing so, the Framers created the three branches of government:
The executive branch
The legislative branch
The judicial branch
Together, the branches of government created a powerful national government with the power to rule the country effectively. It was a drastic change compared to the Articles of Confederation. However, the Constitution also implemented limits on the federal government's powers.
The following sections describe the separate branches, their powers, and the system of checks that limits the other branches of the U.S. government.
Article I: Legislative Branch
Article I of the Constitution begins by stating the following:
"All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives."
Article I places Congress in charge of all lawmaking in the United States and divides legislative power between the Senate and House of Representatives. The Constitution also limits Congress' powers—it may have "all legislative powers," but only the powers "herein granted." Congress cannot pass any law it wishes.
To say Congress has a lot of power is an understatement. As Hamilton noted in The Federalist No. 78, Congress "not only commands the purse but prescribes the rules," in the United States. Article I, Section 8 lists the specific lawmaking powers granted to the legislative branch.
Along with making laws, it also has the following powers (among others):
Declaring war
Raising and funding armies
Regulating commerce
Imposing taxes
Spending money for public purposes
Confirming the president's nominees for positions (e.g., federal judges)
Its powers also act as checks on the executive branch's powers. For example, when the president nominates a candidate for the Supreme Court, members of Congress must vote on the nomination.
Congress also has the power of impeachment with regard to elected and nominated officials. Senators and representatives may also override a president's veto and pass a law that the president chose not to sign into law.
Congress is how the federal government allows the will of the people to shape the country's laws and policies. Citizens elect their senators and representatives, who then listen to their constituents as they propose, debate, and vote on legislation.
For more information about Congress, the Senate, and the House, read FindLaw's article about bicameral legislatures.
Article II: Executive Branch
Article II of the Constitution establishes the executive branch. It states the following:
"The executive Power shall be vested in a President of the United States of America."
The Framers, who had just seen George Washington lead the Continental Army to victory over the British, knew how important having a strong chief executive was. They designed the office of the president with Washington in mind, as he had effectively led the armed forces, and he did not become a dictator while doing so.
In The Federalist No. 70, Hamilton wrote about how important it was to vest the executive branch's power into one person rather than a committee. He noted that not only was it "essential to the protection of the community against foreign attacks; it is not less essential to the steady administration of the laws."
He wrote further that vesting the power in one person was essential for the "security of liberty against the enterprises and assault of ambition, of faction, and of anarchy." As Hamilton saw it, the president "holds the sword of the community."
The president's powers and responsibilities are as follows:
Faithfully execute the laws of the United States
Act as commander-in-chief of the armed forces
Sign bills into law
Veto bills with which they disagree
Represent the United States when dealing with foreign countries
Preserve, protect, and defend the Constitution
Enter into treaties (subject to the Senate's consent)
Recommend legislation to Congress
Report to Congress on the state of the union
Nominate judicial candidates for the Supreme Court and federal courts
The Constitution guaranteed the executive branch's independence by vesting the power in one person. The president typically nominates cabinet members, like the Secretary of State and Secretary of the Treasury, to help them carry out their duties. However, everyone who works in the executive branch follows orders from the president.
Because the three branches of government are co-equals, Congress and the judiciary are not in charge of the president, vice president, or executive officers. Likewise, the president is neither the Congress nor the judiciary's boss. Instead, they work in concert to uphold and defend the Constitution.
The President's power to sign bills into law acts as a check on the legislative branch. Although Congress proposes all the laws, the president must sign them for them to take effect. The legislative branch's power to override a veto also acts as a check against a tyrannical president who could decide not to pass any laws.
The legislature may also impeach a president who commits "high crimes or misdemeanors." Impeaching a president is the only way to remove them from office.
Regarding the president's commander-in-chief powers, although the president chooses how to conduct war, they generally have to wait until Congress declares war to do so. Congress also controls funding for the armed forces and is in charge of raising armies.
Article III: Judicial Branch
Article III of the Constitution establishes the judicial branch, which wields the judicial power of the United States. Article III states the following:
"The judicial Power shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish."
Judicial power refers to the ability of judges and juries to interpret laws and apply them to a set of facts. Because the judicial branch is separate from the other branches, the courts wield this power independently. In other words, the president and Congress have no authority to influence a court's interpretation or application of the law.
In Marbury v. Madison (1803), the Supreme Court answered two important questions:
What happens when Congress passes a federal law that conflicts with the Constitution?
Who determines whether a federal law conflicts with the Constitution?
In answering the first question, the Court held that a federal law is invalid if it conflicts with the Constitution. In answering the second question, the Court determined that the judicial branch has the power to determine whether a federal law conflicts with the Constitution.
Although scholars debate whether Marbury established the idea of judicial review, there is no debate that it was the most significant decision to that point in which the Court determined the Constitution was supreme with regard to conflicting federal laws. It stands for the idea that a law that conflicts with the Constitution is void, and the judicial branch could strike down any such law.
The judicial branch acts as a check on Congress, as the Court will void any law it passes that violates the Constitution. It also checks the executive branch's power because it can declare an action unconstitutional.
For example, when President Harry S. Truman tried to seize private steel mills during the Korean War, the Supreme Court held he did not have the power under the Commander in Chief Clause to do so.
Overall, the judiciary interprets the conduct of other branches. It serves as a check on the other branches' powers and can limit their respective authority to act.
The legislative branch acts as a check on the judicial branch in two ways. First, it must confirm the president's nominees for federal judges or Supreme Court justices. Second, Congress can impeach a federal judge or Supreme Court justice, thereby removing them from office.
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