The framework
The US Constitution, drafted in 1787 and in force since 1789, is the supreme law of the land. It has seven articles. The first three create the branches of the national government: Article I (Congress), Article II (the president) and Article III (the federal courts). Later articles cover relations among the states, amendment, the supremacy of national law and ratification.
Core principles
- Popular sovereignty: government's authority comes from the people.
- Limited government and the rule of law: government may only do what the law allows, and officials are bound by it.
- Separation of powers: legislative, executive and judicial functions are given to different branches.
- Checks and balances: each branch can restrain the others. The president can veto a bill, Congress can override with a two-thirds vote in each chamber, the Senate confirms appointments and ratifies treaties by a two-thirds vote, the courts can strike down laws that conflict with the Constitution, and the House can impeach officials, with the Senate holding the trial.
- Federalism: power is split between the national government and the states.
- Bicameralism: Congress has two chambers, the 435-member House of Representatives and the 100-member Senate.
Enumerated and implied powers
Article I, Section 8 lists the enumerated powers of Congress, such as taxing, borrowing, regulating commerce and declaring war. The necessary and proper clause lets Congress make laws needed to carry out those powers, which supports implied powers. The supremacy clause makes national law prevail over conflicting state law.
Amending the Constitution
The standard path has two steps. A proposal needs a two-thirds vote in both houses of Congress (a convention called by two-thirds of states is the other route, never used). Then three-fourths of the states, which is 38 of 50, must ratify. There have been 27 amendments. The demanding process makes change rare, which gives stability.
The Electoral College
The president is chosen by electors. Each state has as many electors as it has members of Congress, and the District of Columbia has 3 under the 23rd Amendment. The total is 435 + 100 + 3 = 538, so a candidate needs 270 to win.
Worked example: a veto fight
- Congress passes a bill. All 435 House members and 100 senators vote.
- The president vetoes it.
- To override, each chamber needs two-thirds. Two-thirds of 435 is 290; two-thirds of 100 is 67 (rounded up from 66.7).
- If the House reaches 290 and the Senate 67, the bill becomes law without the president's signature.
The example shows a check at work: the president can block the bill, but only a large majority in Congress can overcome the block. Note that the thresholds are based on those present and voting when fewer members attend.