US Gov
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AP US Government & Politics — Cheatsheet

Formulas, exam-day tips, and key terms on one page.

On the exam

How to get a 5

Key terms

FederalismA system of government in which power is divided between a central (national) government and regional (state) governments.
Tenth AmendmentReserves to the states or the people powers not delegated to the federal government. The textual anchor of states' rights arguments.
Commerce clauseGives Congress power over interstate commerce. Read broadly since Gibbons and especially since the New Deal; narrowed somewhat in US v. Lopez.
Necessary and proper clauseGrants Congress power to make laws needed to execute its enumerated powers. The constitutional basis of most federal expansion.
Stare DecisisThe legal principle of determining points in litigation according to precedent.
Judicial reviewThe power to strike down laws and acts as unconstitutional. Not in the Constitution's text; established in Marbury v. Madison.
FilibusterA procedural practice in the Senate to delay or prevent a vote.
ClotureA procedure for terminating debate, especially filibusters, in the Senate.
GerrymanderingDrawing district lines for partisan advantage. "Packing" concentrates opponents in few districts; "cracking" splits them across many.
Incumbency advantageSitting members win re-election at very high rates, helped by name recognition, casework, fundraising and often friendly district lines.
Iron triangleThe stable alliance of a congressional committee, an agency and an interest group, each supplying something the other two need.
Selective incorporationApplying Bill of Rights protections to the states one at a time through the Fourteenth Amendment's due process clause.
Declaration of Independence (1776) — core argumentNatural rights (life, liberty, pursuit of happiness) come before government; government exists by consent of the governed to secure those rights; when it becomes destructive of them, the people may alter or abolish it. Jefferson drew on Locke’s social contract.
Articles of Confederation — three fatal weaknessesNo power to tax (only request funds from states), no national army or executive to enforce law, and amendment required unanimous consent of all 13 states. A one-house Congress with one vote per state; Shays’ Rebellion (1786–87) exposed the design and triggered the Philadelphia Convention.
Federalist No. 10 — thesis in one lineMadison: factions are inevitable because liberty produces them, so control their effects, not their causes; a large (extended) republic with representation makes an oppressive majority faction harder to assemble.
Brutus No. 1 — thesis in one lineAnti-Federalist warning that the necessary and proper and supremacy clauses give the national government unlimited reach, and that a republic covering so vast and diverse a territory cannot represent the people or preserve liberty.
Federalist No. 51 — thesis in one lineMadison: "Ambition must be made to counteract ambition." Separation of powers plus checks and balances gives each branch the constitutional means and personal motive to resist the others, since a government of men cannot rely on virtue alone.
Federalist No. 70 — thesis in one lineHamilton: a single executive provides "decision, activity, secrecy, and despatch," and — crucially — accountability, because a plural executive lets officials hide responsibility behind one another.
Federalist No. 78 — thesis in one lineHamilton: the judiciary is the "least dangerous" branch because it has "neither force nor will, but merely judgment"; life tenure and judicial review let judges defend the Constitution against legislative overreach.
Letter from Birmingham Jail (1963) — key claimsKing defends nonviolent direct action: "injustice anywhere is a threat to justice everywhere"; unjust laws (those a majority imposes on a minority without binding itself) carry a moral duty of civil disobedience; the white moderate who prefers order to justice is a greater obstacle than the outright racist.
The Constitution — the four formal amendment routes and the common oneProposal by two-thirds of both houses of Congress OR by a national convention called by two-thirds of state legislatures; ratification by three-fourths of state legislatures OR three-fourths of state conventions. All but the 21st Amendment used congressional proposal plus state legislature ratification.
Selective incorporation — definition and vehicleThe case-by-case application of Bill of Rights protections to state and local governments through the Fourteenth Amendment’s due process clause. Examples: Gitlow (speech, 1925), Gideon (counsel, 1963), McDonald (arms, 2010).
Federalism tools: categorical vs. block grants and mandatesCategorical grants fund a narrow purpose with strict conditions (maximum federal leverage); block grants fund a broad area with state discretion; unfunded mandates require state action without paying for it (e.g., portions of the Americans with Disabilities Act).
Enumerated vs. implied vs. reserved powersEnumerated: listed in Article I, Section 8 (coin money, declare war). Implied: derived from the necessary and proper clause (national bank, per McCulloch). Reserved: left to the states by the Tenth Amendment (education, most criminal law, licensing).