This project re-imagines American democracy by partitioning U.S. states into contiguous congressional districts that maximize within-district social connections.

A Clear Objective

Redistricting is legally constrained but lacks a clear goal. We propose a simple, intuitive objective: minimize the number of friends separated by district boundaries, keeping cohesive community networks intact.

By using Meta's SCI data (anonymized Facebook friendships), we build districts around real-world connections. The algorithm is blind to politics and competitiveness; it simply ensures that the closest-knit communities are represented together in Congress. (Other reforms like Majority Rule might improve the selection of representatives.)

Allowed Population Deviation

Congressional districts are normally drawn to be equal in population. Because our friendship data is aggregated at the ZIP code level (averaging 30,000 residents), some population imbalance is inevitable. Switch below to see the trade-off: a tighter target (5%) enforces stricter population balance, while a looser target (10%) lets the algorithm save significantly more community ties.

Across all voting districts nationwide, the optimal plan saves --% of social ties cut by the actual 2024 maps.

National Friendship Ties Breakdown

Fractions of all Facebook friendships in the US data

Tiers of Friendship Ties

Facebook friendships in the data are partitioned into five categories:

Within-ZIP: Friendships where both users live in the same ZIP code. These are impossible to split under any redistricting plan.
Preserved: Same-state friendships between different ZIPs kept in the same district by both the actual and optimal plans.
Optimal Cut: Same-state friendships that are cut by the optimal map (and thus cut under both plans).
Cuts Saved: Same-state friendships cut by the 2024 actual map but successfully saved under the optimal plan.
Out-of-State: Friendships crossing state borders, which can never be placed in the same congressional district.

Assignments Table

Download the complete table listing ZIP code (ZCTA) assignments for each congressional district.

Download CSV Table

Swipe to Compare

2024 Actual Districts vs Optimal Districts