The federal government is divided into three branches of government: the legislative branch (Congress), the executive branch (the President), and the judicial branch (the federal courts). Article I gives Congress the power to make federal law, Article II gives the President the power to carry it out, and Article III places the judicial power in the Supreme Court and any lower courts Congress creates.1Legal Information Institute. Article I – Legislative Branch2Legal Information Institute. Article II3Legal Information Institute. Article III The framers did not simply hand each branch its own job and walk away. They built overlapping authorities so the branches would compete with and restrain one another, making concentrated power structurally difficult.
The Legislative Branch: Congress
Congress is bicameral, meaning it has two chambers. Every bill must pass both in identical form before it can reach the President’s desk.
The House of Representatives has 435 voting members, apportioned among the states by population, each serving a two-year term. Because members face reelection so often, the House tends to move with public opinion. It holds the exclusive power to introduce revenue-raising bills, giving it first say over tax policy, and the sole power to impeach federal officials.1Legal Information Institute. Article I – Legislative Branch
The Senate has 100 members, two from each state, serving staggered six-year terms. That structure was designed to insulate the chamber from short-term swings and give smaller states equal footing with larger ones. The Senate’s distinctive powers include confirming presidential nominees for federal judgeships, Cabinet positions, and ambassadorships, and ratifying treaties by a two-thirds vote.1Legal Information Institute. Article I – Legislative Branch
The Executive Branch: The President
Article II vests “the executive power” in the President, who serves as both head of state and head of government for a four-year term. The President’s core constitutional duty is to “take care that the laws be faithfully executed,” which in practice means overseeing the federal bureaucracy that implements what Congress enacts. The President is also Commander in Chief of the armed forces and directs foreign policy by negotiating treaties and appointing ambassadors, both subject to Senate confirmation.2Legal Information Institute. Article II
Beneath the President sit the Vice President, the Cabinet, and hundreds of federal agencies. The Cabinet is made up of the heads of the 15 executive departments, from the Department of State to the Department of Homeland Security, who advise the President and manage the day-to-day work of the federal government.4The White House. Our Government The Executive Branch
The Pardon Power
The President can grant pardons and commutations for federal offenses. The Supreme Court has called this authority “quite broad,” reaching offenses before charges are filed, during prosecution, or after conviction. It has hard limits. The pardon power covers only federal crimes, not state offenses or civil liability. It cannot be used in cases of impeachment. And a President cannot preemptively immunize someone against future criminal conduct. Congress has no authority to restrict pardons; the Supreme Court has held that the power is not subject to legislative control.5Legal Information Institute. Overview of Pardon Power
Executive Orders
Presidents also act through executive orders, directives that carry the force of law within the executive branch. An executive order’s legal authority usually traces back to a statute Congress has passed, though presidents sometimes rely on their own constitutional powers instead.6Federal Judicial Center. Judicial Review of Executive Orders Orders grounded solely in inherent presidential authority rather than congressional authorization are more likely to raise separation-of-powers concerns and face court challenges.
The landmark framework for evaluating presidential power comes from Justice Robert Jackson’s concurrence in Youngstown Sheet & Tube Co. v. Sawyer (1952). Jackson described three tiers: presidential authority is strongest when the President acts with congressional backing, weakest when acting against Congress’s expressed will, and uncertain when Congress has neither authorized nor prohibited the action.7Library of Congress. The Presidents Powers and Youngstown Framework Courts still use this framework when deciding whether a particular executive order is valid, and they can strike down orders when the President lacked authority to issue them or when the order’s substance violates the Constitution.6Federal Judicial Center. Judicial Review of Executive Orders
The Judicial Branch: The Federal Courts
Article III places the federal judicial power in “one Supreme Court, and in such inferior courts as the Congress may from time to time ordain and establish.”3Legal Information Institute. Article III Congress has used that authority to create 94 district courts (the trial level), 13 courts of appeals (the intermediate level), and various specialized courts. At the top sits the Supreme Court with its nine justices.
Federal judges hold their positions “during good Behaviour,” which in practice means life tenure. They can only be removed through impeachment. That insulation from political pressure is intentional. It allows judges to make unpopular decisions when the Constitution demands them without worrying about reelection or salary cuts.3Legal Information Institute. Article III
Judicial Review
The judiciary’s most consequential power, the authority to strike down laws and government actions that violate the Constitution, appears nowhere in the Constitution’s text. The Supreme Court established it for itself in Marbury v. Madison (1803), reasoning that because the Constitution is “superior paramount law,” any legislative act that conflicts with it is void, and it falls to courts to say so.8Library of Congress. Marbury v Madison and Judicial Review Chief Justice John Marshall’s opinion framed it memorably: “It is emphatically the province and duty of the judicial department to say what the law is.”9Federal Judicial Center. Marbury v Madison (1803) Since Marbury, the Court has used judicial review to invalidate federal statutes, state laws, and executive actions, making the judiciary the ultimate referee of constitutional disputes between the other two branches.
How the Branches Check Each Other
The separation of powers would be theoretical without a mechanism to enforce it. That mechanism is the system of checks and balances, specific powers each branch can use to push back against the others.
The Presidential Veto
When Congress passes a bill, it goes to the President. The President can sign it or veto it. A vetoed bill returns to the chamber where it originated, and Congress can override the veto only if two-thirds of both the House and Senate vote to do so, a high bar that rarely succeeds.10Legal Information Institute. The Veto Power
There is also the pocket veto. If Congress sends a bill to the President and then adjourns before ten days have elapsed (Sundays excluded), the President can kill the bill simply by not signing it. Unlike a regular veto, Congress gets no chance to override a pocket veto. The bill dies, and legislators must start over from scratch.11Legal Information Institute. Veto Power
Senate Confirmation of Nominees
The President nominates federal judges, Cabinet secretaries, ambassadors, and other senior officials, but none can take office without Senate confirmation. This gives the Senate enormous leverage over the composition of the executive branch and the judiciary. A single controversial nominee can become a weeks-long political battle, and the threat of rejection shapes whom the President nominates in the first place.2Legal Information Institute. Article II
Congressional Oversight
Beyond passing laws, Congress can investigate the executive branch and demand information. The Supreme Court has called this investigative authority “indispensable” to the ability to legislate effectively. Congress can compel testimony and documents through subpoenas, and committees regularly hold hearings to scrutinize how agencies spend money and enforce the law.12Supreme Court of the United States. Trump et al v Mazars USA LLP et al
Congressional subpoena power is not unlimited. The investigation must serve a legitimate legislative purpose, and Congress cannot use subpoenas purely for law enforcement, since that authority belongs to the executive branch and the courts. When subpoenas target the President’s personal information, the Supreme Court has required courts to apply heightened scrutiny, ensuring the subpoena is no broader than necessary and that Congress cannot obtain the same information from other sources.12Supreme Court of the United States. Trump et al v Mazars USA LLP et al
Impeachment and Removal From Office
Impeachment is the most dramatic check one branch can exercise on another. The Constitution authorizes the removal of the President, Vice President, and all civil officers of the United States for “Treason, Bribery, or other high Crimes and Misdemeanors.” That phrase was borrowed from English parliamentary practice and is generally understood to cover serious abuses of public trust, not just ordinary criminal offenses. The Constitutional Convention specifically rejected “maladministration” as a ground for removal, signaling that mere incompetence is not enough.13Legal Information Institute. Impeachable Offenses Historical Background
The process has two stages. First, the House investigates and votes on articles of impeachment. A simple majority is sufficient to impeach, which is roughly equivalent to an indictment: it formally accuses the official but does not remove them from office. The matter then moves to the Senate, which conducts a trial. When the President is on trial, the Chief Justice of the Supreme Court presides. Conviction requires a two-thirds vote of the senators present, and the immediate consequence is removal from office.14Legal Information Institute. Overview of Impeachment Trials The Senate can then vote separately, by simple majority, to bar the official from ever holding federal office again.
The Power of the Purse
Money is one of Congress’s strongest tools for controlling the other branches. The Constitution gives Congress alone the power to tax and spend, a provision known as the Spending Clause.15Library of Congress. Overview of Spending Clause No federal agency and no president can spend a dollar Congress has not appropriated. The principle is backed by the Antideficiency Act, which prohibits agencies from spending money or incurring financial obligations beyond what Congress has authorized.16U.S. Government Accountability Office. Shutdowns/Lapses in Appropriations
When Congress fails to pass spending bills before the October 1 start of the fiscal year, a government shutdown occurs. Most federal agencies must stop operations and furlough employees, and workers cannot volunteer their services without pay except in narrow circumstances. Activities funded through permanent appropriations (like Social Security benefits) continue, as do functions necessary to protect human life and government property.16U.S. Government Accountability Office. Shutdowns/Lapses in Appropriations
War Powers
The Constitution splits military authority between the branches in a way that has generated conflict since the founding. Congress holds the power to declare war, raise armies, and fund military operations. The President serves as Commander in Chief of the armed forces. In practice, presidents have deployed troops hundreds of times without a formal declaration of war from Congress, leading to a persistent tug-of-war over who actually controls the decision to go to war.
Congress attempted to resolve this tension with the War Powers Resolution of 1973.17Office of the Law Revision Counsel. 50 US Code Chapter 33 – War Powers Resolution Under the resolution, the President must consult with Congress before sending troops into hostilities whenever possible, and must submit a written report to Congress within 48 hours of any deployment. That report must explain the circumstances, the legal authority for the action, and the expected scope and duration. The President must continue reporting at least every six months for as long as forces remain deployed. If Congress does not authorize the military action within 60 days, the President is generally required to withdraw the troops within an additional 30 days.
Every president since 1973 has questioned whether the War Powers Resolution is constitutional, arguing it infringes on the Commander in Chief’s inherent authority. Congress has rarely forced a direct confrontation. The result is a gray area where both branches claim overlapping authority, and the practical balance depends more on political dynamics than legal certainty.