Back to Unit 5

Political Parties

Party Functions, Realignment, Dealignment, and the Two-Party System

AP Exam Connection

Unit 5 — Political Participation (20–27% of AP exam)

Political parties appear in MC questions and FRQ 4 (Argument Essay). AP focuses especially on party functions, realignment/dealignment, why a two-party system persists, and party influence on voter behavior and government.

RealignmentDealignmentThird Parties

Memory Tricks

"Realignment = voters SWITCH parties. Dealignment = voters LEAVE parties." In realignment, a critical election shifts large blocs of voters from one party to another. In dealignment, voters abandon party identification entirely and call themselves independents.

"Third parties lose seats, win ideas." Third parties almost never win national office under winner-take-all rules, but they succeed by introducing ideas that major parties later adopt. The Populist and Progressive party platforms were mostly absorbed by the major parties within a generation.

"The New Deal coalition broke on civil rights." FDR built a coalition of Northern liberals, labor unions, urban ethnic voters, and Southern whites. LBJ's civil rights legislation shattered the Southern wing — triggering the most significant party realignment of the 20th century.

What Political Parties Do

Political parties are the primary linkage institution connecting citizens to government. Their functions are broader than most students realize — they extend well beyond elections.

Recruit and nominate candidates

Parties identify and support candidates for office at every level from school board to president. Primary elections are the formal mechanism.

Organize the government

The majority party in Congress selects committee chairs, controls the legislative agenda, and determines leadership positions (Speaker, Majority Leader).

Mobilize voters (GOTV)

Parties conduct voter registration drives, canvassing, phone banking, and get-out-the-vote operations to maximize turnout among supporters.

Simplify voter choice

Party labels serve as information shortcuts — voters who know little about a candidate can use party affiliation to infer ideological positions.

Write party platforms

Platforms state the party's policy positions and goals. While not binding, platforms signal priorities and influence government once the party wins office.

Connect interest groups

Parties aggregate the interests of multiple groups into governing coalitions, negotiating among labor, business, identity groups, and ideological factions.

Realignment and Dealignment

ConceptDefinitionKey Example
RealignmentCritical election shifts large voter blocs between parties, reshaping coalition for a generation1932 — FDR's New Deal coalition; 1964–80 — Southern realignment to GOP
DealignmentVoters weaken or abandon party identification; rise of independentsPost-1970s growth of independents; split-ticket voting
Critical ElectionA realigning election that produces a durable shift in the party coalition1932 (Roosevelt), 1980 (Reagan)
Party PolarizationGrowing ideological distance between the two major parties; increased partisan sortingPost-1990s Congress; decline of moderate Republicans and conservative Democrats

Third Parties

Third parties face structural disadvantages that make winning office nearly impossible, but they play important roles in American politics as pressure valves, idea incubators, and spoilers.

Structural barriers

Winner-take-all rules mean third parties win no seats even with substantial vote shares. Ballot access laws vary by state and often require extensive petitioning. Campaign finance law disadvantages new parties. The presidential debate system has historically excluded third-party candidates.

Spoiler effect

Third parties may draw enough votes from a major party to affect the outcome without winning themselves. Ross Perot (1992) likely drew more from Bush than Clinton. Ralph Nader (2000) in Florida is frequently cited as affecting that race's outcome.

Idea adoption

The most successful third parties historically are those whose ideas get absorbed by a major party. The Populists' monetary reform agenda became Democratic policy under Bryan and later FDR. Progressive era reforms were absorbed by both parties.

AP Exam Connections

Key Concept

Party Realignment

Know the New Deal coalition (1932) and the Southern realignment (1964–1980). These are the two most-tested examples.

Key Concept

Dealignment

Distinct from realignment — voters leave parties rather than switch. Growing share of self-identified independents.

Key Concept

Duverger's Law

Winner-take-all systems produce two-party competition. This is the structural explanation for why third parties fail.

FRQ 4 Essay

Party Functions

AP FRQ 4 frequently asks about the role of parties in democracy. Know all six functions and be able to evaluate their contribution.

Key Concept

Party Platforms

Know that platforms are aspirational, not binding. Presidential candidates sometimes deviate from platform positions once in office.

Key Concept

Partisan Sorting

The process by which ideologically consistent voters have sorted into the appropriate party. Moderates have declined in both parties.

Writing Practice

AP-Style FRQ Prompt

Political parties serve multiple functions in a democratic system, connecting citizens, candidates, and government.

  1. Describe one function political parties perform in the electoral process and explain how it contributes to democratic participation.
  2. Explain why the United States has a two-party system rather than a multi-party system, referencing the electoral rules that produce this outcome.
  3. Evaluate whether party dealignment strengthens or weakens democratic governance in the United States, providing one piece of evidence for your position.

Tip: Part C is evaluative — the AP expects a clear claim with evidence, not just description. A strong answer to Part C takes a position on dealignment (weakens because voters are less predictable and parties are less accountable; OR strengthens because independent voters force candidates toward the center) and backs it with specific evidence.

Key Takeaways

  • Parties perform six key functions: nominating candidates, organizing government, mobilizing voters, simplifying choice, writing platforms, and connecting interest groups
  • The two-party system persists because winner-take-all electoral rules (Duverger's Law) structurally disadvantage third parties
  • Realignment = voters switch parties in a critical election; Dealignment = voters abandon party identification
  • The New Deal coalition (1932) and the Southern realignment (1960s–80s) are the two most-tested realignments on AP exams
  • Third parties rarely win office but succeed by introducing ideas that major parties eventually adopt
  • Party polarization has increased since the 1990s — moderate members of both parties have declined sharply
Political Parties — Quick Check
1 / 3 · Score: 0

Which of the following BEST explains why the United States has a two-party system rather than a multi-party system?

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