Questions

Just a Mac. Every state comes ready to open, with Census precincts and presidential results (2024 in 36 states, 2020 in the rest), and you can also bring your own precinct shapefile and election data.

Macs with Apple silicon, running a recent version of macOS. Nothing else to install.

A map drawn by a random process that follows only the basic rules (equal population, connected districts) and never looks at votes. Thousands of them show what an ordinary map of a state looks like, which is how you can tell whether a particular map is unusual.

Each score you turn on gives the map a penalty, 0 being perfect, and its weight says how much that penalty counts. The total is their weighted sum, and the optimizer keeps changes that lower it. The app shows the arithmetic for any map.

Yes. Every state's enacted map is one click away, and you can load any plan as a CSV of precinct IDs and districts, then score it, improve it, or compare it with neutral maps.

Precinct boundaries and population from the 2020 Census, joined to election results by Harvard's ALARM Project (CC BY-SA 4.0). The 2024 presidential results for 36 states come through Dave's Redistricting (CC BY-SA 4.0) from the Redistricting Data Hub, the New York Times and state election offices, used under their non-commercial terms; the rest use the Voting and Election Science Team's 2020 results (CC BY 4.0). District plans come from the Census Bureau's TIGER/Line files. You can also load your own data.

Yes. Open any precinct shapefile with a population column; votes, counties and demographics are optional and turn on the matching scores.

Yes: a one-page report, share images, poster art, GeoJSON, shapefiles and precinct-to-district CSVs that Dave's Redistricting and Districtr can import.

Yes. The code is on GitHub.