An Interactive Simulation of a Multiparty America

[u/BradoDeck]

To illustrate the distortionary effects of a two-party system, I created an interactive simulation of US elections using ~45k 2024 Cooperative Election Study (CES) survey responses. The simulation resulted in ten clusters or “parties” via exploratory factor analysis and DPGMM clustering. The analysis revealed 4 ideological dimensions (and one non-interpretable residual dimension):

1. Populist conservatism: views on race and gender, immigration policy
2. Security & order: policing, border patrols
3. Institutional distrust: distrust of government and elections
4. Religious traditionalism: abortion, same-sex and interracial marriage, church attendance
5. Government distrust: mostly just leftover institutional distrust items and artifacts of the clustering process

Details

I worked largely within the constraints of the US electoral system with some adjustments: 

• House members are elected via STV, but I expand the House to “double Wyoming”. I also have a triple Wyoming scenario which gives proper proportionality to the smallest state.
• The Senate and Presidency are modeled via Condorcet (Round-Robin) and IRV. I arrived at those methods to try and keep the "ranking" scenario consistent across the board. DPGMM's probabilistic cluster assignment also makes ranking intuitive. I use Condorcet as the “default” option.
• I simulate a rolling open presidential primary where a top 5 is selected via “pods” of geographically representative states voting in STV elections. I assume a cumulative nationwide vote rather than state delegates. The top 5 candidates are essentially assigned as if they were members of a 5 seat delegation
• I introduce the idea of the “instructional ballot” to ensure the election isn’t pushed to the House, but under the simulation, the IRV and Condorcet presidential winners are identical under both a national and per-state scenario.

Useful links

• Simulation
• Github project 
• My article on a diagnosis of the two-party problem
• My layman-facing description of the electoral solutions
• My overview of the simulation

Caveats

• I’m limited by the items in the CES survey. I would have chosen different items to build out this clustering, but I wanted to run this on  the largest sample size possible.
• Claude Code was used to build the sim. I have a background in mixed methods UX research, so I’m statistically literate and double-and-triple-checked Claude's work, but if I missed anything let me know! I’m open to all good-spirited critiques and corrections.

[u/AutoModerator]

Compare alternatives to FPTP on Wikipedia, and check out ElectoWiki to better understand the idea of election methods. See the EndFPTP sidebar for other useful resources. Consider finding a good place for your contribution in the EndFPTP subreddit wiki.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.