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

Published

August 10, 2021

AK AL AR AZ CA CO CT DE FL GA HI IA ID IL IN KS KY LA MA MD ME MI MN MO MS MT NC ND NE NH NJ NM NV NY OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WY DC USA

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.

Citation

BibTeX citation:
@online{t._kenny2021,
  author = {T. Kenny, Christopher and McCartan, Cory},
  title = {2020 {Redistricting} {Data} {Files}},
  date = {2021-08-10},
  url = {https://alarm-redist.github.io/posts/2021-08-10-census-2020/},
  langid = {en}
}
For attribution, please cite this work as:
T. Kenny, Christopher, and Cory McCartan. 2021. “2020 Redistricting Data Files.” August 10, 2021. https://alarm-redist.github.io/posts/2021-08-10-census-2020/.