Republican Party growth by county, June 2 - July 14, 2026

Statewide, the Republican Party has grown by 7,350 registered voters ahead of the July 28 runoff election for the Republican nomination for governor. Much of that growth stems from party affiliation switches, county auditors say, but it can also include new registrations, such as new voters coming of age and voters moving to the state.

A map shows the growth in Republican voters between June 2 and July 14. Counties with the largest growth include Minnehaha (1,802), Pennington (1,023), Lincoln (785), Brown (482) and Lawrence (289).

(Please use a modern browser to see the interactive version of this visualization)

The voter registration deadline for the July 28 runoff was July 13.

Chart: Makenzie HuberSource: South Dakota Secretary of State's OfficeGet the dataCreated with Datawrapper