US Electoral College
Electoral College: 538 electors, 270 to win, winner-take-all in most states
US Electoral College
How the US president is actually elected — not by popular vote
538 total (House + Senate + 3 DC). 270 needed to win. 48 states: winner-take-all. Maine and Nebraska award by congressional district. Critics: small states and swing states over-represented.
Duverger's Law
Duverger's Law: winner-take-all → two dominant parties
Duverger's Law
Why the US has two parties — it's structural, not accidental
In plurality (winner-take-all) elections, voters abandon third parties (wasted vote) and they collapse. Proportional representation → more parties. UK/USA = two-party; Germany/Netherlands = multi-party.
Incumbent Advantage
Incumbents win >90% of House re-election races — name recognition + resources
Incumbent Advantage
Why sitting members of Congress almost always win re-election
Name recognition, franking privilege (free mail), easier fundraising, ability to deliver constituent services, and gerrymandering all favor incumbents.
Voter Turnout
Turnout: Education is the strongest single predictor
Voter Turnout
What drives people to vote — and what doesn't
Education level: strongest predictor. Registration requirements reduce turnout (unique to US). Competitive races increase turnout. Age: older voters turn out more. Race and income also correlate strongly.
Gerrymandering
Gerrymandering: drawing districts to favor one party — packing and cracking
Gerrymandering
How partisan district drawing distorts electoral outcomes
Packing: concentrate opposition voters in a few districts (they win big there, wasted votes). Cracking: spread opposition voters thinly across many districts (they lose everywhere). Named after Governor Elbridge Gerry (1812).
Electoral Systems
Voting systems: plurality (winner-takes-all), proportional representation, ranked-choice, mixed
Electoral Systems
Different ways of translating votes into seats — with very different outcomes
Plurality (FPTP): candidate with most votes wins — tends to produce two parties (Duverger's Law). Proportional representation: seats allocated by vote share — more parties, better minority representation. Ranked-choice voting: voters rank candidates, instant runoff eliminates last-place finisher. Mixed: combines elements (Germany).
Campaign Finance
Campaign finance: PACs, Super PACs, dark money. Citizens United (2010): corporations = free speech.
Campaign Finance
Money in politics — the rules and the loopholes
Citizens United v FEC (2010): political spending by corporations and associations is protected free speech — cannot be limited. Super PACs: can raise and spend unlimited money but cannot coordinate with campaigns. Dark money: 501(c)(4) nonprofits spend on elections without disclosing donors. Hard money: direct contributions to candidates — limited.
Political Socialization
Political socialization: how people acquire political beliefs — family is the strongest influence
Political Socialization
How citizens develop their political views
Primary agents: family (strongest predictor of party identification), school (civic education), peers, media, religion. Party identification: often adopts parents' party. Generational effect: political coming-of-age during significant events shapes lifetime views (Great Depression → Democrat, Reagan era → Republican). Life-cycle effects: people become more conservative with age.
Political Polarization
Partisan polarization: ideological distance between parties has increased dramatically since 1970s
Political Polarization
Why American politics has become so divided
Congressional voting records: Republicans and Democrats rarely overlap ideologically — used to overlap substantially. Causes: geographic sorting, primary elections selecting extreme candidates, media fragmentation (partisan media), negative partisanship (voting against the other party more than for your own). Consequences: gridlock, declining bipartisanship.
Public Opinion and Polling
Public opinion polls: sampling error, question wording, response bias — not all polls are equal
Public Opinion and Polling
How polls work — and why they sometimes fail
Random sample: every person has equal chance of being selected — the only valid method. Sampling error: ±3% margin of error at 95% confidence for n=1,000. Question wording effects: small changes dramatically alter responses. Response bias: people give socially acceptable answers. Likely voter screen: likely voters differ from registered voters.
Party Identification Trends
Dealignment: voters less attached to parties. Realignment: major shift in party coalitions.
Party Identification Trends
How Americans' relationship with political parties has changed
Party identification: psychological attachment to a party — most stable political attitude. Dealignment: growing share of voters identify as independent (now ~40%). Realignment: critical elections shift party coalitions. 1932: New Deal coalition. 1968: Southern realignment (Solid South became Republican). 1994: Republican Revolution.
Median Voter Theorem
Median voter theorem: in two-party systems, both parties converge to the political center
Median Voter Theorem
Why both parties should move toward the center — and why they often don't
Downs: rational parties maximize votes by moving toward the median voter's position. If voters distributed along a left-right spectrum, both parties converge to the middle. Why it fails: primary elections reward extreme positions, base mobilization matters more in low-turnout elections, party activists are ideologically extreme.