The framers split federal power three ways, then gave each branch tools to block the other two. No branch can act alone for long. That friction is the design: it forces bargaining, slows rash decisions, and makes it hard for any one faction to take control.
“Ambition must be made to counteract ambition.” — James Madison, Federalist No. 51
Part 1
Who does what
Separation of powers: each branch gets its own job, its own people, and its own way of being chosen. Different terms and different electorates mean they rarely all shift at once.
Article I
Legislative · Congress
Job
Writes the laws and controls the money.
Who
House: 435 members, 2-year terms, seats by population. Senate: 100 members, 6-year staggered terms, 2 per state.
Pass bills, tax and spend
Declare war, regulate commerce
House impeaches; Senate tries
Senate confirms nominees, ratifies treaties
Article II
Executive · President
Job
Carries out and enforces the laws.
Who
President and Vice President, 4-year terms via the Electoral College; two-term limit (22nd Amendment). Runs the federal departments and agencies.
Sign or veto bills
Commander in chief
Nominate judges and officials
Negotiate treaties, grant pardons
Article III
Judicial · Courts
Job
Interprets the laws and the Constitution in actual cases.
Who
Supreme Court (9 justices, a number set by Congress) plus lower federal courts. Judges serve “during good behaviour”, in practice for life.
Decide cases and controversies
Judicial review: void unconstitutional laws and acts
Settle disputes between states
Part 2
The checks, branch by branch
Each arrow is a power one branch holds over another. Tap an arrow, a branch, or use the selectors.
Fromon
Part 3
Walk a bill through the gauntlet
Pick what happens at each step and watch which check kicks in. Every path that ends in a law needed at least two branches to agree.