Data Center provides four party affiliation types you can use to filter voter lists. Political Party values vary by state, as some states may register voters by political parties and other State Parties may use their own voter-scoring system. All voters are assigned an Calculated Party score when possible.

Voter Lookup results and reports will display the most appropriate party type for the state. For example, a voter search in California will return a voter with Official Party, voter records in Minnesota will display the Observed Party value and Texas voter results will display the Calculated Party value. 

A count result may contain no voters if a party value is selected which is not appropriate for the state. When in doubt, use Calculated Party to filter voter lists. All party types are included for any list type when exporting a voter list.

Use Calculated Party scores for filtering your voter list for a voter's likely party affiliation. Scores are generally determined from a voter's partisan primary ballot vote history, universe tags, and voter model projects. A "Swing" voter may not have sufficient vote history or voter tag information for calculating a partisan score.

Under Illinois election law, there are no Registered Republicans, Registered

Democrats, or Registered Independents. Therefore, GOP Data Center uses a mathematical formula based on the voter’s statewide partisan Primary Ballot history to determine their Observed Party.

1 - Hard Republican

Has voted in 2 or more Republican Primary Elections and no Democrat Primary

Elections (out of the last 3 Primary Elections on record)

2 - Soft Republican

Has voted only in 1 Republican Primary Election and no Democrat Primary Elections

(out of the last 3 Primary Elections on record)

3 – Mixed Primary Voter

Has voted in both Republican and Democrat primaries (out of the last 3 Primary Elections on record)

4 - Independent

Has voted in 1 or more General Elections but no Primary Elections (out of the last 3 Primary Elections on record)

5 - Soft Democrat

Has voted only in 1 Democrat Primary Election and no Republican Primary Elections (out of the last 3 Primary Elections on record)

6 - Hard Democrat

Voted in 2 or more Democrat Primary Elections and no Republican Primary Elections (out of the last 3 Primary Elections on record)

7 - New Registrant

Registered to vote since last even-numbered year General Election on record but has

not voted in a Primary yet

0 - Unidentified

Registered to vote but has not voted in ANY election in an even-numbered year

The Washington State Republican Party has updated Observed Party to use 2020 and 2024 voter participation tags (updated April 2024).

The California database uses 31 expanded Household Party types for selection in the Basic/Advanced Counts tools (added July 2021). The selection criteria and description for each Household Party type are described below.