2020 Redistricting Data Files

Census and election data joined together for use in redistricting and voting rights analysis.

Authors

Affiliations

Christopher T. Kenny

Department of Government, Harvard University

Cory McCartan

Department of Statistics, Harvard University

The ALARM Project is glad to provide precinct-level demographic and election data from the 2020 decennial census and the Voting and Election Science Team which have been tidied and joined together using 2020 precinct boundaries. Where 2020 precinct boundaries are not available, Census block-level data is provided instead, and where no VEST data is available, only demographic information is provided. Code to generate the data from these sources is included; the entire workflow is open-source and reproducible.

Getting the data

Download individual states’ data below, or download a ZIP of all the data here. Our repository also contains more detailed data, as well as code and instructions for programmatic downloading, adding shapefile geometries, and other use cases.

Please make sure to cite the Voting and Election Science Team and the U.S. Census Bureau. Consult the license for information on modifying and sharing the data and/or code.

2020 state data

  Alabama VTDs     al_2020_vtd.csv

  Alaska VTDs     ak_2020_vtd.csv

  Arizona VTDs     az_2020_vtd.csv

  Arkansas VTDs     ar_2020_vtd.csv

  California Census blocks     ca_2020_block.csv

  Colorado VTDs     co_2020_vtd.csv

  Connecticut VTDs     ct_2020_vtd.csv

  Delaware VTDs     de_2020_vtd.csv

  District of Columbia VTDs     dc_2020_vtd.csv

  Florida VTDs     fl_2020_vtd.csv

  Georgia VTDs     ga_2020_vtd.csv

  Hawaii Census blocks     hi_2020_block.csv

  Idaho VTDs     id_2020_vtd.csv

  Illinois VTDs     il_2020_vtd.csv

  Indiana VTDs     in_2020_vtd.csv

  Iowa VTDs     ia_2020_vtd.csv

  Kansas VTDs     ks_2020_vtd.csv

  Kentucky VTDs     ky_2020_vtd.csv

  Louisiana VTDs     la_2020_vtd.csv

  Maine VTDs     me_2020_vtd.csv

  Maryland VTDs     md_2020_vtd.csv

  Massachusetts VTDs     ma_2020_vtd.csv

  Michigan VTDs     mi_2020_vtd.csv

  Minnesota VTDs     mn_2020_vtd.csv

  Mississippi VTDs     ms_2020_vtd.csv

  Missouri VTDs     mo_2020_vtd.csv

  Montana VTDs     mt_2020_vtd.csv

  Nebraska VTDs     ne_2020_vtd.csv

  Nevada VTDs     nv_2020_vtd.csv

  New Hampshire VTDs     nh_2020_vtd.csv

  New Jersey VTDs     nj_2020_vtd.csv

  New Mexico VTDs     nm_2020_vtd.csv

  New York VTDs     ny_2020_vtd.csv

  North Carolina VTDs     nc_2020_vtd.csv

  North Dakota VTDs     nd_2020_vtd.csv

  Ohio VTDs     oh_2020_vtd.csv

  Oklahoma VTDs     ok_2020_vtd.csv

  Oregon Census blocks     or_2020_block.csv

  Pennsylvania VTDs     pa_2020_vtd.csv

  Rhode Island VTDs     ri_2020_vtd.csv

  South Carolina VTDs     sc_2020_vtd.csv

  South Dakota VTDs     sd_2020_vtd.csv

  Tennessee VTDs     tn_2020_vtd.csv

  Texas VTDs     tx_2020_vtd.csv

  Utah VTDs     ut_2020_vtd.csv

  Vermont VTDs     vt_2020_vtd.csv

  Virginia VTDs     va_2020_vtd.csv

  Washington VTDs     wa_2020_vtd.csv

  West Virginia VTDs     wv_2020_vtd.csv

  Wisconsin VTDs     wi_2020_vtd.csv

  Wyoming VTDs     wy_2020_vtd.csv

Using the data

Data Format

Each data table contains several identification columns, a set of census-derived demographic columns, and a set of VEST-derived election columns.

• GEOID20 is the unique identifier for a precinct or Census block. The state and county of the precinct or block are also provided.

• Census variables are prefixed with pop_ or vap_, depending on whether they are for the entire population or the voting-age population. Suffixes refer to racial and ethnic categories, as follows:

  • _hisp: Hispanic or Latino (of any race)
  • _white: White alone, not Hispanic or Latino
  • _black: Black or African American alone, not Hispanic or Latino
  • _aian: American Indian and Alaska Native alone, not Hispanic or Latino
  • _asian: Asian alone, not Hispanic or Latino
  • _nhpi: Native Hawaiian and Other Pacific Islander alone, not Hispanic or Latino
  • _other: Some Other Race alone, not Hispanic or Latino
  • _two: Population of two or more races, not Hispanic or Latino

• Election variables consist of average vote counts for Democratic and Republican candidates. The adv_## and arv_## columns report the average vote count in the ## election, across all statewide races contested by both parties. The ndv and nrv columns further average the vote counts across all available election years. For specific statewide races, you may download the files in vest-2020/ and join them to the data using the GEOID20 column.

More Tools

• For redistricting and voting rights analysis, we recommend the redist package.
• For pre-processing and tidying data for redistricting analysis, we recommend the geomander package.
• For more custom tabulations of the 2020 census data, we recommend the PL94171 package.
• For general-purpose census data processing, we recommend the censable package.
• For alternate data unaffected by Census differential privacy, you may want to consider FCC block-level estimates, available using the blockpop package.

Technical notes

To produce election data using 2020 precinct boundaries, election results were projected down to the 2010 block level using voting-age population as weights. Results for 2020 blocks were then estimated using 2010 blocks and the land-use-based crosswalk files from VEST. Finally, 2020 blocks were aggregated to 2020 precincts using the Census’ 2020 block assignment files.

2010 Data Addendum

If you are looking for a similar construction for 2010 data, please see here.