ElectIndex Supporter
The National Atlas is a Supporter feature
Every election since 2008 at precinct level, the full Census and ACS, religious adherence, Trump approval, and ecological inference you can run on any election — all on one map. Built by the ElectIndex model, and part of a Supporter membership at any tier.
About the National Atlas
Every election and every Census variable, on one map
The ElectIndex National Atlas is a reference map of American political geography. It puts more than a decade of precinct-level election results and the full sweep of Census and American Community Survey data onto a single set of block groups, so any two things can be compared in the same place at the same resolution.
Election layers cover presidential, Senate, governor, House and statewide down-ballot races, drawn from precinct returns and apportioned to block groups by voting-age population. Where a race was not held, or where returns were never published at precinct level, the map says so plainly rather than colouring the gap as a tie.
Census layers span population and race, education, income and poverty, employment and occupation, housing and tenure, household structure, nativity and language, veterans, disability, health insurance, mobility and broadband — each at block-group resolution, alongside derived measures such as population density and urban-rural classification.
Every election
Presidential, Senate, governor, House and down-ballot races from 2008 to 2024, at precinct level on one geography — read them by state, county, district (any lines since 1976) or precinct.
The Census, mapped
Race, age, education, income, housing, occupation, ancestry, language, veterans, disability, broadband and more — every variable at block-group resolution.
How groups voted
Ecological inference runs live in your browser: break any election — or Trump approval — down by race, education, income or tenure.
Data credits
The Atlas is built entirely from public data and the ElectIndex model, every source traced to the build step that consumes it. With thanks to:
Election results3 sources
Dave's Redistricting — vtd_data
Every contest in the Atlas, read by scripts/atlas/build_elections.py. Packaged by DRA under CC BY-SA 4.0.
Voting and Election Science Team (VEST)
The precinct returns behind those cycles in the DRA package. CC BY 4.0.
2024 presidential precinct results, via the DRA package and the block-group files the 2024 layer is built from.
Population and geography4 sources
U.S. Census Bureau — 2020 Census (PL 94-171)
The Atlas substrate: population, voting-age population and race by block, plus the voting-district and county-subdivision crosswalks. Read by scripts/atlas/build_substrate.py.
U.S. Census Bureau — American Community Survey
Every Census layer beyond the decennial count. Fetched by scripts/atlas/fetch_acs.py.
U.S. Census Bureau — cartographic boundary files
The block-group geometry the map draws, tiled by scripts/atlas/build_atlas_tiles.mjs.
U.S. Census Bureau — Gazetteer & TIGER/Line
The background map's city labels and road network, projected by scripts/atlas/build_cities.mjs from the Simulator's basemap bundle.
Religion1 source
2020 U.S. Religion Census (ASARB)
Religious adherence, rolled into families by scripts/atlas/build_religion.py. Adherents claimed by congregations, not a survey of belief.
The ElectIndex model2 sources
Ecological inference
Estimated group-level voting, regressed per county from precinct returns and composition by assets/atlas/atlas-ei.js. Ecological estimates — no survey anchor, subject to aggregation bias.
Presidential approval by area
ElectIndex's own model output, published alongside the 2026 forecast.
These organisations are not affiliated with, and do not endorse, ElectIndex. Election data packaged by Dave's Redistricting is used under CC BY-SA 4.0; derived election layers carry the same licence. Ecological estimates are model output, not counts.
We aim to credit every data source. See one we should attribute? Let us know.