Congressional Redistricting Map Auditor

Audit congressional and legislative redistricting maps for equal-population standard deviation, Polsby-Popper geometric compactness, county subdivisions, and partisan efficiency gaps under state and federal judicial review criteria.

Efficiency Gap (EG)
+18.4%
Biased toward GOP (Threshold: ±7%)
Max Pop Deviation
4.82%
Ideal: 750,000 / dist (Target < 1%)
Mean Polsby-Popper
0.24
Low compactness (Tentacles / bizarre)
Seat Projections
3 R - 1 D
52.4% R / 47.6% D Statewide
Interactive County & Precinct Allocation
Select a target district on the left panel, then tap any county below to reallocate it.
Total Population: 3,000,000 | 4 Congressional Districts
District Total Pop Pop Deviation GOP Vote % DEM Vote % Projected Winner Compactness Counties

Redistricting Standards & Judicial Scrutiny Framework

The Efficiency Gap (Partisan Gerrymandering)

Pioneered by Nicholas Stephanopoulos and Eric McGhee, the Efficiency Gap calculates the net difference in wasted votes (votes cast for a losing candidate plus surplus votes cast for a winning candidate) divided by total votes cast. An efficiency gap exceeding ±7% historically indicates an unconstitutional partisan entrenchment that survives multiple electoral tides.

Polsby-Popper Compactness Ratio

Defined mathematically as 4π × Area / (Perimeter)², measuring how closely a district resembles a perfect circle (1.0). Irregular tentacles, serpentine corridors, and bizarre contortions produce low ratios (below 0.20), serving as prime judicial red flags for improper motive under state constitutional compactness guarantees.

Equipopulation & One Person, One Vote

Under Article I, Section 2 and Wesberry v. Sanders, congressional districts within a state must strive for near-mathematical population equality. Deviation above 1-2% without compelling justification (such as respecting municipal or county boundaries) invites immediate judicial striking.

County Splitting & Communities of Interest

Dividing municipal cores or intact rural counties among multiple districts to dilute political cohesion ("cracking") or confining entire opposing demographics into a single isolated stronghold ("packing") violates traditional redistricting principles enforceable under state high court jurisdiction.

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