amazon.co.ukUS Politics: Comparative Politics
A* comparative revision for Edexcel 9PL0 Paper 3: US constitution, Congress, presidency, Supreme Court and democracy, synthesised with the UK through rational choice, cultural and structural theories.
🎯 Learning Objectives
- Outline the three comparative theories - rational choice, cultural and structural - and apply each to a US/UK difference or similarity (Edexcel 9PL0 Paper 3, comparative theories) (AO1/AO2).
- Compare the US codified constitution and federalism with the UK's uncodified, unitary-devolved arrangement (AO1/AO2).
- Compare Congress with Parliament and the presidency with the premiership, including divided government, checks and gridlock (AO2).
- Compare the US Supreme Court's powers and appointment process with the UK Supreme Court, and civil rights protection in both (AO2).
- Compare US and UK elections, parties and participation, including the Electoral College, primaries and campaign finance (AO2).
- Write comparative essays that synthesise US and UK content and use comparative theories to reach substantiated judgements (AO3).
📋 Key Definitions and Core Concepts
Codified constitution: A single authoritative written document establishing the powers and limits of government (US Constitution, 1787); entrenched against casual change by a demanding amendment process.
Separation of powers: Legislative, executive and judicial powers vested in separate institutions and separate personnel - Congress, president and courts in the USA.
Checks and balances: Each branch limits the others: presidential veto and appointments, congressional override and impeachment, judicial review.
Federalism: Power divided between a national government and states each supreme in their own sphere; 'dual' federalism (clear spheres, pre-1937) gave way to 'cooperative' federalism (grants-in-aid, mandates).
Judicial review: The power of courts to strike down laws and actions incompatible with the constitution; established in Marbury v Madison (1803).
Executive order: A presidential directive carrying the force of law within existing statute; a key tool of informal - and 'imperial' - presidential power.
Divided government: One party holds the presidency while the other controls one or both chambers of Congress; a structural driver of gridlock.
Electoral College: The institution formally electing the president: 538 electors allocated state by state, winner-take-all in 48 states; 270 needed to win; can split from the popular vote (2000, 2016).
Swing (battleground) state: A competitive state whose outcome can decide the election, concentrating campaign attention (e.g. Pennsylvania, Wisconsin, Arizona).
Imperial presidency: Presidential power exceeding constitutional intent, exercised through executive orders, war powers and unilateral action (Schlesinger's term, 1973).
Affirmative action: Race- or gender-conscious admissions and hiring policies remedying past discrimination; ended in college admissions by SFFA v Harvard/UNC (2023).
Rational choice theory: Comparative theory: politicians and voters act to maximise self-interest - parties converge on the median voter (Downs), presidents bargain, legislators pork-barrel.
📌 Key Points
Comparative essays demand synthesis: two-way comparison plus explicit use of rational choice, cultural or structural theory - not parallel description of each system.
Constitutions: US codified and entrenched (27 amendments since 1787) vs UK uncodified and flexible; separation of powers vs parliamentary fusion.
Executive: president checks Congress (veto, appointments) but faces gridlock under divided government; PM fuses executive and legislature and usually dominates it.
Courts: US Supreme Court strikes down legislation (Marbury 1803) with politicised appointments; UK Supreme Court (2009) only declares incompatibility under HRA s.4.
Elections: fixed terms, Electoral College swing-state focus and popular-vote splits (2000, 2016) vs UK flexible dates, FPTP and referendums.
Comparative theories: rational choice, cultural, structural (Edexcel Paper 3)
Edexcel 9PL0 Paper 3 requires you to synthesise US and UK politics through three named theories - Section B essays reward explicit use of them, not parallel description of each system.
- Rational choice: political actors maximise self-interest. Presidents veto to extract concessions; senators block appointments for partisan gain and pork-barrel for re-election; UK MPs weigh careers against party loyalty. Explains behaviour that looks institutionally similar in both systems.
- Cultural theory: political values explain differences. American exceptionalism - individualism, distrust of central government, religiosity, gun culture, frontier history - explains the weaker US welfare state, the persistence of the death penalty and hostility to federal healthcare, against the UK's more deferential, collectivist strands.
- Structural theory: institutions and structures explain outcomes. Separation of powers produces gridlock; parliamentary fusion produces executive dominance; federalism produces state policy divergence (Texas vs California on guns, abortion, immigration); racial and religious structures shape US civil rights politics.
| Theory | Core claim | US/UK example |
|---|---|---|
| Rational choice | Actors maximise self-interest | Presidential veto bargaining; pork-barrel; convergence of parties on the median voter (Downs) |
| Cultural | Values and political culture explain differences | US individualism/distrust of federal power vs UK deference; explains weaker US welfare state |
| Structural | Institutions explain outcomes | Separation of powers - gridlock; parliamentary sovereignty - executive dominance; federalism - state divergence |
Exam tip: real questions often name a theory ('Using the comparative theories...') or leave theory open. Either way, weave one lens through the whole essay and use a second as a counterpoint - that is what separates Level 5 answers.
The three lenses also explain similarity as well as difference: rational choice predicts two-party convergence in both systems; culture explains a shared suspicion of over-mighty executives; structure explains why both constitutions limit power, differently. Level 5 answers use the lenses to explain why a similarity exists - not only why systems differ - and always name the theory in play.
Constitutions and federalism (5.1)
USA: a codified constitution (1787), entrenched by Article V - proposal by two-thirds of both chambers plus ratification by three-quarters of states; only 27 amendments since 1787. Separation of powers plus checks and balances fragments power; the Bill of Rights (1791) protects liberties against all branches. Federalism: the 10th Amendment reserves powers to the states; dual federalism's clear spheres became cooperative after the New Deal (grants-in-aid, mandates). Modern fault lines: immigration (Arizona v US, 2012), abortion returned to the states by Dobbs v Jackson (2022), gun regulation, marijuana legalisation - states as 'laboratories of democracy'.
UK: uncodified, unentrenched, drawn from statute, common law, conventions and works of authority; parliamentary sovereignty means any rule can be changed by simple majority. Unitary in principle, quasi-federal in practice since devolution (1998-99) - but Westminster remains sovereign and can legislate for the whole UK.
Comparisons to deploy: codified vs uncodified; entrenched vs flexible (the UK adapts quickly - the US constitution changes rarely); separation of powers vs fusion; federal vs unitary-devolved; rights protection via entrenched Bill of Rights and judicial review vs the Human Rights Act 1998's declarations of incompatibility. Theory: structural theory explains why the flexible UK constitution concentrates power while the rigid US one fragments it; cultural theory explains the US founders' distrust of central authority.
The amendment hurdle has consequences: rights evolve in the US through judicial interpretation rather than amendment - Brown, Roe, Obergefell and Dobbs all changed rights without changing a word of the Constitution. Appointments are therefore rights policy by other means, which is why the Court is so politically contested. Federalism also has consequences for elections: the Electoral College and state-run elections are structural artefacts of the founders' design - structural theory and cultural theory are both needed to explain US politics.
Congress and presidency compared with Parliament and PM (5.2, 5.3)
Congress: bicameral with equal state representation in the Senate (two per state) and population-based House; exclusive powers - declare war, ratify treaties, confirm appointments (Senate), originate revenue bills (House). Powerful standing committees; Senate filibuster - ended only by cloture (60 votes) - gives minorities a supermajority veto. Congress is independent of the executive: no confidence vote can dissolve it. Parliament: the Lords revises but is unelected; the Commons dominates via party discipline (whips, Salisbury convention); departmental select committees are weaker checks.
Presidency: formal powers - Commander-in-Chief, treaties, appointments (Senate confirmation), veto, pardon, State of the Union; informal powers - the bully pulpit, executive orders, crisis leadership, the world stage. Divided government breeds gridlock: vetoes, blocked nominations, shutdowns. The imperial presidency label captures power exceeding constitutional intent (war powers, unilateral action); executive orders are easily reversed by successors (travel bans; Biden's day-one reversals). PM: primus inter pares, fused with the legislature, usually commands a majority; patronage and collective responsibility; checked by party rebellion (e.g. the Brexit defeats of 2019) - and the 2022 Dissolution and Calling of Parliament Act restored snap-election calling.
Theory: structural theory explains the core contrast - separation of personnel makes the president weaker domestically than a PM with a majority, but stronger in foreign affairs; rational choice explains veto bargaining and pork-barrel; culture explains the US suspicion of concentrated executive power.
Congressional checks in practice: the Senate has rejected or stalled numerous judicial and executive nominees; impeachment has been used against three presidents (Johnson 1868, Clinton 1998-99, Trump twice in 2019 and 2021) without a conviction; government shutdowns (2013; 2018-19, the longest at 35 days) show budget leverage in action. Parliament's equivalent power - confidence - is decisive but rare (1979). Divided government is not automatic gridlock: the 1986 tax reform and the 2021 infrastructure act passed under divided control.
Supreme Court and civil rights (5.4)
US Supreme Court: nine justices, nominated by the president, confirmed by the Senate, life tenure; appointments are highly politicised (e.g. Barrett, 2020, days before the election). Judicial review (Marbury v Madison, 1803) lets it strike down federal and state law: Brown v Board (1954) desegregated schools; Roe v Wade (1973) was overturned by Dobbs (2022); Obergefell (2015) same-sex marriage; Citizens United (2010) campaign spending; SFFA v Harvard/UNC (2023) ended race-conscious admissions. Debate: activism vs restraint, strict vs loose construction. UK Supreme Court: created by the Constitutional Reform Act 2005, appointed via an independent commission to age 70; it reviews executive action but cannot strike down primary legislation - only declare incompatibility (HRA 1998 s.4), which Parliament may ignore.
Civil rights: the US route is constitutional litigation and federal statute - 13th-15th Amendments, Civil Rights Act 1964, Voting Rights Act 1965, affirmative action debates - driven by a pluralist, litigious rights culture. The UK route is parliamentary statute - Equality Act 2010, HRA - supervised by courts with softer powers.
Comparisons: the US Court is arguably the most powerful court in the democratic world (strike-down plus life tenure plus politicised appointment); the UK Court is a subordinate high court. Theory: structural (constitutional supremacy vs parliamentary sovereignty), cultural (US litigation culture), rational (interest-group litigation strategies).
The Roe-to-Dobbs arc (1973-2022) is the best single illustration of the US Court's power: one generation of judges created a constitutional right, another removed it, and the political system re-aligned around the vacancy. Nothing comparable exists in the UK - no court can create or remove a statutory right outright, only prompt Parliament to act - and the arc is the best evidence in the activism-vs-restraint debate.
Democracy, elections and participation (5.5) + synthesis technique
USA: fixed four-year presidential terms; the Electoral College concentrates campaigns on swing states and can split from the popular vote (2000 Bush v Gore; 2016 Clinton's popular-vote win). Primaries give voters direct candidate selection; turnout, historically low, rose in 2020 to its highest since 1900; Citizens United (2010) unleashed super PAC spending; incumbents enjoy structural advantages. UK: parliamentary elections with flexible dates (restored 2022), FPTP entrenching two-party dominance but with more fluid support; referendums (2016 Brexit) as direct democracy; party funding regulated more tightly than post-Citizens United America.
Comparisons to deploy: candidate selection (primaries vs centrally approved lists); direct democracy usage; money in politics; turnout trends; the Electoral College's unequal vote weight vs FPTP's wasted votes - both systems distort, differently.
Turnout and money compared: US turnout was historically low (below 60% in 1996 and 2000) but reached about two-thirds in 2020, the highest since 1900; UK turnout fell from 71% (1997) to 59% (2001) before recovering. Campaign finance is the sharper contrast: post-Citizens United super PACs spend billions, while UK spending is capped and party funding regulated - cultural theory (US free-speech culture) and rational choice (donors as investors) both explain the difference. FPTP's wasted votes versus the College's unequal vote weight is a ready-made comparison pair.
Exam technique: Edexcel Paper 3 comparative essays (30 marks)
Sustained two-way comparison - similarities AND differences, point-for-point, not two parallel essays. Explicit comparative theory: name rational choice, cultural or structural theory and apply it; use a second lens as counterpoint. A substantiated judgement with stated criteria in the conclusion. AQA students (no US option on 7152) can still use this page for idea-level comparisons and as context for Paper 2's presidency/constitution themes. Traps: describing each system separately; asserting 'the US is more democratic' without criteria; ignoring a named theory when the question invites it.
💡 Worked Example
Exam-style: To what extent is the US presidency more powerful than the UK premiership? [30 marks] (Edexcel 9PL0 Paper 3, Section B) --- AND --- Using the comparative theories, to what extent are the US and UK constitutions similar? [30 marks]
Mark-scheme logic: Presidency question: AO1 - accurate comparative knowledge (formal powers: veto, appointments, Commander-in-Chief vs royal assent, patronage, collective responsibility; fixed terms; divided government). AO2 - analysis of strengths and limits: the president checks Congress but faces gridlock under divided government and reversals of executive orders; the PM fuses executive and legislature and usually dominates, but is checked by party rebellion and lost majorities. AO3 - judgement with criteria: domestically the PM is usually more powerful (fusion, majority, control of the legislative timetable); in foreign affairs the president is stronger (Commander-in-Chief, executive agreements); structural theory explains the contrast (separation vs fusion). Constitutional question: AO1 - codified vs uncodified, entrenchment, separation of powers vs fusion, federal vs unitary-devolved, entrenched Bill of Rights vs HRA. AO2 - similarities (both limit government, protect rights, establish representative democracy) and differences (rigidity vs flexibility; judicial supremacy vs parliamentary sovereignty). AO3 - judgement: more different than similar, or vice versa, with criteria and a named theory applied throughout.
❓ Practice Questions & Mark Schemes
To what extent are the US and UK constitutions similar? [30 marks]
Answer: Similarities: both limit government through checks (US: separation of powers and entrenchment; UK: conventions, statute and courts); both protect rights (Bill of Rights and judicial review vs HRA and Equality Act); both establish representative democracy with periodic elections. Differences: codified and entrenched (27 amendments since 1787) vs uncodified and flexible (changed by simple majority); separation of powers with separate personnel vs fusion of executive and legislature; federalism vs unitary principle with devolved quasi-federalism; constitutional supremacy with judicial strike-down vs parliamentary sovereignty. Theory: structural theory explains the divergent concentration of power; culture explains the founders' distrust of central authority. Judgement: more different than similar - the shared vocabulary of limited government conceals opposite structural logics (rigid fragmentation vs flexible concentration); state criteria (entrenchment, power distribution, rights protection) and conclude.
To what extent is Congress more powerful than Parliament? [30 marks]
Answer: Congress: independent of the executive (no confidence mechanism), exclusive powers (declare war, ratify treaties, confirm appointments), powerful standing committees, filibuster leverage; it can block and shape a president's agenda. Parliament: formally sovereign (can legislate on anything) but usually dominated by the executive through whips, patronage and majority control of the timetable; departmental select committees are weaker; yet it has defied executives (the Brexit defeats of 2019; e.g. the Indicative Votes). Theory: structural theory - separation of powers vs fusion explains who controls the legislature in practice; rational choice explains pork-barrel and rebellion incentives. Judgement: Congress is more powerful against the executive, but Parliament is more powerful in absolute terms (sovereignty); the comparison depends on the criterion chosen - state it and conclude.
To what extent are the US Supreme Court and UK Supreme Court similar? [30 marks]
Answer: Similarities: both independent of the executive; both interpret rights and review executive action; both wield significant political influence (Dobbs 2022, prorogation ruling 2019). Differences: judicial review with strike-down power (Marbury 1803; Roe 1973; Dobbs 2022) vs declarations of incompatibility only (HRA s.4, ignored by Parliament at will); politicised appointments (presidential nomination, Senate confirmation, life tenure) vs independent commission, age-70 retirement; constitutional supremacy in the US vs subordination to parliamentary sovereignty in the UK. Theory: structural theory - the US court's power flows from constitutional supremacy, the UK court's limits from parliamentary sovereignty; culture explains the US litigation-driven rights politics. Judgement: superficially similar in role, fundamentally different in power - the US Court is a co-equal branch, the UK Court a subordinate high court; state criteria and conclude.
To what extent does the Electoral College undermine US democracy? [30 marks]
Answer: Undermines: two popular-vote/electoral-vote splits (2000, 2016) mean the winner lacked majority consent; swing-state focus concentrates campaigns on a handful of states (Pennsylvania, Wisconsin, Arizona) and neglects safe states; votes in small states are weighted more heavily than votes in large ones; third parties are crushed by winner-take-all. Supports: it embodies federalism - states, not just individuals, elect the president; it usually delivers decisive, prompt outcomes; it forces broad coalitions. Theory: structural theory explains the distortion (winner-take-all allocation); rational choice explains campaign concentration; cultural theory explains why reform fails (small-state pride, constitutional entrenchment). Judgement: on majoritarian criteria the College undermines democracy; on federal criteria it reflects the founders' design - argue both, state criteria, conclude with a substantiated view.
To what extent are rational choice theory and cultural theory useful for comparing US and UK politics? [30 marks]
Answer: Rational choice: usefully explains behaviour - presidential veto bargaining, senatorial pork-barrel, MP career calculations, party convergence on the median voter (Downs); its limits are that identical incentives produce different outcomes in the two systems, so institutions must matter too. Cultural theory: usefully explains divergence - American exceptionalism (individualism, distrust of federal power, religiosity) explains the weaker US welfare state and gun politics against UK collectivism; its limits are the risk of over-generalisation and of ignoring structural drivers. Structural theory as counterpoint: separation of powers vs fusion, federal vs unitary structures explain what neither behaviour nor values alone can. Judgement: neither theory suffices alone - Edexcel rewards synthesis; the strongest answers apply one named theory systematically and use a second as critique. Structure: theory 1 with examples, theory 2 with examples, counterpoint, judgement.