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Key Data Notes for Expert Witnesses and Special Masters

Information for Expert Witnesses, Special Masters or anyone using our data in litigation

Data Types

Refer to our About Our Data page to see a list of all of the types of datasets we host including voter file, CVAP, disaggregated demographic and election data, population projections, official redistricting datasets by state, newly passed and previous legislative boundaries (state and congressional), incumbent addresses and more.

We host unique datasets of interest:

  • disaggregated CVAP to the 2020 block level
  • incumbent address data (by request only)
  • population projections
  • voter file data
  • disaggregated election results to the 2020 block level
  • “Endogenous” state legislative or congressional results joined to precinct boundaries. These “extended” files join additional election results to VEST 2016, 2017, 2018, 2019, and 2020 precinct boundaries (primary and general). These datasets may also contain additional statewide results that aren’t included in existing files, such as referenda, ballot questions, and other statewide races.

Filter by type of dataset on the state data pages to see what we have available (such as “precinct boundaries and election results”, “demographic”, “legislative boundaries”, etc.)


For all datasets, we include an enclosed README. Refer to the README for more information about our sources, dates accessed, processing steps, and field names. You can view our READMEs on the datasets page prior to downloading.

For our precinct boundaries and election results files, we often include a Validation Report or Election Results Verification report which details our effort at replicating the production of the file. If you have additional questions about the datasets please contact the help desk at for information on our processing.


Reach out to our help desk for any assistance or clarification about our data, and to let us know what you are working on.

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