The Three Branches of US Government

The United States Constitution establishes a government divided into three co-equal branches. This separation of powers, combined with a robust system of checks and balances, prevents any single branch from accumulating too much power — a direct response to the founders' fear of tyranny.

The Legislative Branch — Congress (Article I)

Congress is the lawmaking branch. Article I is the longest article in the Constitution, reflecting the founders' belief that the legislature would be the most powerful branch.

Structure: Bicameral Legislature

Congress is divided into two chambers:

The Senate:

• 100 senators (2 per state, regardless of population)
• 6-year terms (staggered — 1/3 elected every 2 years)
• Presiding officer: Vice President of the United States (votes only to break ties)
• President pro tempore: senior majority senator, presides in VP's absence
• Special powers: Ratify treaties (2/3 vote), confirm presidential nominations (simple majority), try impeachments, elect the VP if the Electoral College deadlocks

The House of Representatives:

• 435 representatives (allocated by population; reapportioned every 10 years after the Census)
• 2-year terms (all seats up for election every even-numbered year)
• Presiding officer: Speaker of the House (elected by the majority party)
• Special powers: Originate revenue (tax) bills, initiate impeachment

Powers of Congress

Enumerated (express) powers (Article I, Section 8):

• Tax and spend for the general welfare
• Borrow money
• Regulate interstate and foreign commerce
• Coin money
• Declare war
• Raise and support armies and a navy
• Establish post offices and post roads
• Grant patents and copyrights
• Create lower federal courts

The Necessary and Proper Clause ("Elastic Clause") — Article I, Section 8: Congress can make all laws "necessary and proper" to carry out its enumerated powers. This clause has been interpreted broadly to give Congress extensive implied powers (McCulloch v. Maryland, 1819).

How a Bill Becomes a Law

1. Introduction: A member of Congress introduces a bill
2. Committee referral: Bill is assigned to a relevant committee; most bills die here
3. Committee action: Hearings, markup (amendments), vote out of committee
4. Full chamber vote: Debate and vote in the originating chamber
5. Other chamber: Repeats the process in the other chamber; if different versions pass, a Conference Committee reconciles them
6. Presidential action: President signs (becomes law), vetoes (returns to Congress), or does nothing
   • If Congress is in session and President does nothing for 10 days → becomes law
   • If Congress adjourns and President does nothing for 10 days → pocket veto
7. Veto override: Congress can override a veto with a 2/3 majority of both chambers

The Executive Branch — The President (Article II)

The President

• 4-year term; maximum 2 terms (22nd Amendment, 1951)
• Must be a natural-born citizen, at least 35 years old, and a resident of the US for 14 years
• Commander in Chief of the armed forces
• Chief executive: Executes and enforces federal law through ~2 million federal employees and 15 Cabinet departments

Presidential Powers

Power	Description
Veto	Reject legislation passed by Congress
Commander in Chief	Direct the armed forces; conduct military operations
Treaties	Negotiate treaties (require 2/3 Senate ratification)
Appointments	Nominate federal judges, ambassadors, Cabinet members (Senate confirmation required)
Pardons	Grant pardons for federal offenses (except impeachment)
Executive orders	Direct the executive branch without Congressional approval (within Constitutional limits)
State of the Union	Required to periodically "give to the Congress information of the State of the Union"

The Cabinet

15 executive departments, each led by a secretary who serves in the Cabinet:

• State Department (foreign affairs)
• Treasury Department
• Defense Department
• Justice Department (Attorney General)
• Homeland Security (created 2002 post-9/11)
• ... and 10 more

The Vice President

• Presides over the Senate; breaks tie votes
• First in the presidential line of succession (Speaker of the House is second; President pro tempore third)
• Assumes the presidency if the President dies, resigns, or is removed (25th Amendment)

Checks on the President

• Congress can override vetoes (2/3 majority)
• Senate must confirm major appointments
• Senate must ratify treaties
• Congress controls the federal budget (power of the purse)
• Impeachment: House impeaches (simple majority); Senate tries and convicts (2/3 majority) → removal from office
• Judicial review: Courts can strike down executive actions

The Judicial Branch — Federal Courts (Article III)

Structure of the Federal Courts

Supreme Court of the United States (SCOTUS) — 9 justices
    ↑ Appeals
U.S. Courts of Appeals — 13 circuits (circuit courts)
    ↑ Appeals
U.S. District Courts — 94 districts (trial courts)

U.S. District Courts: Trial courts of the federal system; where most federal cases begin. At least one per state.

U.S. Courts of Appeals: Intermediate appellate courts. 11 numbered circuits + D.C. Circuit + Federal Circuit. Three-judge panels hear most cases.

U.S. Supreme Court: Final arbiter. Nine justices (one Chief Justice + 8 Associate Justices). Decides which cases to hear via certiorari (cert) petitions — accepts ~1% of petitions (~70–80 cases/year).

Judicial Appointments

Federal judges — including Supreme Court Justices — are:

• Nominated by the President
• Confirmed by the Senate (simple majority since 2017)
• Serve lifetime terms "during good behavior"
• Removed only by impeachment (no justice has ever been removed by impeachment)

Lifetime tenure insulates judges from political pressure — they can rule based on law rather than electoral concerns.

Judicial Review

The Supreme Court's most significant power — not explicitly in the Constitution, but established in Marbury v. Madison (1803):

The Court can strike down any act of Congress, executive action, or state law that violates the Constitution.

This makes SCOTUS the ultimate check on both the legislative and executive branches.

Landmark Supreme Court Cases

Case	Year	Holding
Marbury v. Madison	1803	Established judicial review
McCulloch v. Maryland	1819	Broad implied powers of Congress; federal supremacy
Brown v. Board of Education	1954	Segregated public schools are unconstitutional (14th Amendment)
Miranda v. Arizona	1966	Police must inform suspects of rights (5th and 6th Amendments)
Roe v. Wade	1973	Abortion rights (overturned by Dobbs v. Jackson, 2022)
United States v. Nixon	1974	Executive privilege is not absolute
District of Columbia v. Heller	2008	2nd Amendment protects individual right to keep firearms at home
Obergefell v. Hodges	2015	Same-sex marriage is a constitutional right
Dobbs v. Jackson Women's Health	2022	Overturned Roe v. Wade; abortion regulation returned to states

The System of Checks and Balances

Branch	Can Check	How
Congress	President	Veto override (2/3), impeachment, power of the purse, treaty ratification, appointment confirmation
Congress	Judiciary	Confirm/reject nominees, impeach judges, propose constitutional amendments, change court jurisdiction
President	Congress	Veto legislation, call special sessions, recommend legislation
President	Judiciary	Nominate judges; pardon defendants
Courts	Congress	Strike down laws as unconstitutional
Courts	President	Strike down executive actions; cannot strike down pardons

Study Snapshot

Three Branches — Congress (Senate + House; lawmaking power), President (execute laws; Commander in Chief; veto; appointments), Federal Courts (judicial review; lifetime tenure; SCOTUS), and mutual checks and balances.

Concept Flow

Check Your Understanding

1. Why does the Senate have equal representation (2 per state) while the House is proportional to population?
2. How does a presidential veto get overridden, and how often does Congress successfully do this?
3. What is "judicial review" and why is it significant that it is not written explicitly in the Constitution?
4. What distinguishes the Senate's special powers from the House's special powers?