The Structure of Party Competition

1. Parties in US Democracy

Political Parties & Elections

  1. Electoral mobilization and candidate selection

  2. Parties are coherent brands for imperfectly informed voters

  3. Persistance of two party system

Political Parties in Government

  1. Coalition formation and maintenance

  2. Coordination within/across branches

  3. Agenda control and policy making

2. The Unidimensional Spatial Model: Utility Functions

Connectedness: two alternatives, A > B or B > A

Transitivity: If C > A and A > B, then C > B

  1. Utility Function: for each individual i, a mapping from set of alternatives to a number, with each alternative x assigned a unique value ui(x)

    1. Alternative Point / X = the candidate’s position

  2. Preference Profile: the set of all utility functions (for all i )

  3. Euclidean Spatial Preferences: each ui(x) characterized by an ideal point xi and utility is decreasing in the distance between xi and the alternative x, |x-xi|

    1. Ideal Point: the policy that maximizes the individual’s utility

      1. The desired voter’s position

    2. Voting for the candidate closest to you in position

The farther away the ideal point (voter’s position) is from alternative point / x (candidate’s position), the worse it is for you / the voter ‌‌

3. Hotelling-Downs Spatial Voting Model

A1. Suppose alternatives representable as points on a line

A2. Suppose all voters have Euclidean preferences over alternatives (summarized by ideal points)

A3. Suppose simple majority rule with no abstention (declining to vote)

A4. Suppose two office-seeking candidates who take unconstrained positions on the line

For any distribution of voter ideal points, there is a Nash Equilibrium (NE) in which both candidates converge to the ideal point of the median voter

→ The candidate moving closer to the center is desirable because they are moving closer to more voters but in real life, candidates do not do this; most candidates do not become moderate

4. The Median Voter Theorem

Separate from Hotelling-Downs Theorem !!!!

A1. Suppose alternatives representable as points on a line

A2. Suppose all voters have Euclidean preferences over alternatives (summarized by ideal points)

A3. Suppose simple majority rule with no abstention (declining to vote)

Given A1 - A3 are correct, the median voter’s ideal point is unbeatable in pairwise competition

5. The Normative Implication

The ‘Classic View” of democratic responsiveness

The median ideal point minimizes the sum of absolute distances to other ideal points, so the best move is to always position at the median point
?

→ Not so fast! In reality, politicians take on extreme positions and there is significant ideological polarization in the US

In the real world, a voter may want a more extreme representative than yourself because though they are more extreme, they will not be the sole decision maker once in office. The representative will join more moderate politicians of their party which will somewhat balance the extremities due to having to compromise

6. Constraints on Party Position-Taking

Party: an organization that seeks to elect a candidate to public office

A party needs to attract members, resources, and a candidate to operate

Typically people with more extreme ideals are more motivated— they are the people who run for office

→ This goes against the Hotelling-Downs Theorem; a candidate cannot share a median position because they have to come across as different in order to justify support against the opponent

The Hotelling-Downs Theorem also falls short because candidates don’t only care about winning and appeasing the median voter; they also care about their positions and policies so converging to the center doesn’t make sense

There are benefits to brand identification; it creates easily identifiable party cues for voters

7. Primaries

Open Primaries: any registered voter can vote for a candidate in any party

Closed Primaries: any registered voter with a particular party’s membership can vote for said party’s candidate

Top-Two Candidates Open Primary: the top two from a single ballot voting election proceed to general elections— no voting restriction

The median voter in a primary is not the same as a median voter in the general election !!

When the moderate members of each party stay home, the primary median voters shift to more extreme but more extreme candidates fare worse

When extreme candidates win primaries, there is mobilization and polarization of the opposition; the other party’s base is more motivated

8. The Decisive Vote

The importance of the state comes from

  1. How close the forecast is supposed to be (closeness)

  2. How swingable are centrist voters (uncertainty)

  3. How likely would it be that flipping state would change outcome (decisiveness)

Candidates are not tactical and make mistakes in choosing where to divert focus on state electoral voters in presidential general elections

9. Why Only 2 Major Parties?

Hypothesis 1: National Consensus

  1. Few divisions among voters— there isn’t enough disagreement to warrant multiple parties

Hypothesis 2: Election Law and Cooptation

  1. Winner takes all vs. proportional elections

    1. Minor parties will merge with the big party as that is more beneficial than running in Single-Member Districts

    2. Fear of a “wasted vote”

    3. There is no incentive for small parties to compete

  2. Cooptation: parties diverge to prevent third-parties from forming

10. Polarization

The American constitutional system is not well designed to reap the benefits of polarized parties

There is more likelihood of gridlock when polarized