Primaries for South Dakota Senate See Four Republican Incumbents Lose Re-Nomination
All 35 seats in the South Dakota Senate are up this year.
The Democratic and Republican primaries occurred today in South Dakota to select candidates for the November 2026 general election. This post covers the races for all 35 seats in the State Senate. Separate posts will be covering the primaries for federal and statewide executive offices, every seat in the State House of Representatives, and county contests.
In South Dakota, a candidate must achieve at least 35% in the primary to receive their party’s nomination. If that doesn’t happen, then the top two finishers will advance to a runoff scheduled for July 28, 2026.
The general election for all 35 seats in the South Dakota Senate will be held on November 3, 2026.
District 1:
No candidate qualified for the Democratic primary.
Incumbent Michael Rohl won the Republican primary.
District 2:
No candidate qualified for the Democratic primary.
State Representative John Sjaarda won the Republican primary with 62.1% (2,309) against State Representative David Kull with 37.9% (1,411). 3,720 votes counted.
District 3:
No candidate qualified for the Democratic primary.
Business owner Katherine Washnok won the Republican primary with 63.5% (2,508) against incumbent Carl Perry with 36.5% (1,443). 3,951 votes counted.
District 4:
No candidate qualified for the Democratic primary.
Incumbent Stephanie Sauder won the Republican primary with 51.0% (2,804) against former State Senator Tim Begalka with 49.0% (2,699). 5,503 votes counted.
District 5:
No candidate qualified for the Democratic primary.
Incumbent Glen Vilhauer won the Republican primary with 59.1% (1,852) against State Representative Josephine Garcia with 40.9% (1,283). 3,135 votes counted.
District 6:
No candidate qualified for the Democratic primary.
Incumbent Ernie Otten Jr. won the Republican primary.
District 7:
No candidate qualified for the Democratic primary.
Incumbent Tim Reed won the Republican primary.
District 8:
No candidate qualified for the Democratic primary.
Incumbent Casey Crabtree won the Republican primary.
District 9:
No candidate qualified for the Democratic primary.
Incumbent Joy Hohn won the Republican primary with 58.5% (1,626) against entrepreneur Daryl Christensen with 41.5% (1,154). 2,780 votes counted.
District 10:
Incumbent Liz Larson won the Democratic primary.
Bank representative Michael Dupic won the Republican primary.
District 11:
2024 state house nominee Aaron Matson won the Democratic primary.
Incumbent Chris Karr won the Republican primary with 60.9% (1,587) against attorney Graham Oey with 39.1% (1,018). 2,605 votes counted.
District 12:
Communications director Joe Zweifel won the Democratic primary.
State pharmacy board executive director Kari Shanard-Koenders won the Republican primary.
District 13:
No candidate qualified for the Democratic primary.
Incumbent Sue Peterson won the Republican primary with 58.0% (2,405) against business consultant Dan Kippley with 42.0% (1,741). 4,146 votes counted.
District 14:
No candidate qualified for the Democratic primary.
Incumbent Larry Zikmund won the Republican primary with 71.9% (2,449) against former State Representative R. Shawn Tornow with 28.1% (956). 3,405 votes counted.
District 15:
State Representative Erik Muckey won the Democratic primary.
2022/24 nominee Brenda Lawrence won the Republican primary.
District 16:
No candidate qualified for the Democratic primary.
Incumbent Kevin Jensen won the Republican primary.
District 17:
No candidate qualified for the Democratic primary.
Incumbent Sydney Davis won the Republican primary with 76.5% (1,944) against Army veteran Jeffrey Church with 23.5% (596). 2,540 votes counted.
District 18:
Kay Swihart won the Democratic primary.
Incumbent Lauren Nelson won the Republican primary with 53.4% (1,885) against former State Senator Jean Hunhoff with 46.6% (1,642). 3,527 votes counted.
District 19:
2022 nominee Russell Graeff won the Democratic primary.
Incumbent Kyle Schoenfish won the Republican primary with 65.8% (2,985) against business owner Donna Olson with 34.2% (1,551). 4,536 votes counted.
District 20:
No candidate qualified for the Democratic primary.
Incumbent Paul Miskimins won the Republican primary.
District 21:
2020/22/24 nominee Dan Andersson won the Democratic primary.
Incumbent MyKala Voita won the Republican primary with 59.0% (3,273) against former State Senator Erin Tobin with 41.0% (2,271). 5,544 votes counted.
District 22:
No candidate qualified for the Democratic primary.
Incumbent Brandon Wipf won the Republican primary.
District 23:
No candidate qualified for the Democratic primary.
Incumbent Mark Lapka won the Republican primary.
District 24:
No candidate qualified for the Democratic primary.
Incumbent Jim Mehlhaff won the Republican primary with 55.4% (3,391) against former prosecutor Brian Murphy with 29.0% (1,773) and rancher Mark Nelson with 15.6% (958). 6,122 votes counted.
District 25:
No candidate qualified for the Democratic primary.
Incumbent Tom Pischke won the Republican primary.
District 26:
Former State Senator Shawn Bordeaux won the Democratic primary with 60.3% (762) against government consultant Troy Lunderman with 39.7% (502). 1,264 votes counted.
State Representative Rebecca Reimer won the Republican primary with 53.3% (1,210) against incumbent Tamara Grove with 46.7% (1,062). 2,272 votes counted.
District 27:
Principal Celestine Stadnick won the Democratic primary.
2024 nominee Anthony Kathol won the Republican primary.
District 28:
No candidate qualified for the Democratic primary.
Incumbent J. Sam Marty won the Republican primary with 51.8% (2,095) against former State Senator Ryan Maher with 48.2% (1,950). 4,045 votes counted.
District 29:
No candidate qualified for the Democratic primary.
Army veteran Bill Meirose won the Republican primary with 51.5% (2,280) against incumbent John Carley with 48.5% (2,151). 4,431 votes counted.
District 30:
No candidate qualified for the Democratic primary.
Incumbent Amber Hulse won the Republican primary with 66.5% (4,139) against former State Senator Julie Frye-Mueller with 33.5% (2,084). 6,223 votes counted.
District 31:
No candidate qualified for the Democratic primary.
Incumbent Randy Deibert won the Republican primary with 56.4% (2,692) against former State Representative John Teupel with 43.6% (2,077). 4,769 votes counted.
District 32:
Archaeologist Jeff Shelton won the Democratic primary.
Incumbent Helene Duhamel won the Republican primary with 63.4% (1,316) against chemist Karen McNeal with 36.6% (759). 2,075 votes counted.
District 33:
Christopher Baumgartner won the Democratic primary.
Former State Senator David Johnson won the Republican primary with 51.8% (2,409) against incumbent Curt Voight with 48.2% (2,240). 4,649 votes counted.
District 34:
Business owner Michael Calabrese won the Democratic primary.
Incumbent Taffy Howard won the Republican primary with 57.0% (2,334) against former Rapid City city attorney Jason Green with 43.0% (1,760). 4,094 votes counted.
District 35:
No candidate qualified for the Democratic primary.
Incumbent Greg Blanc won the Republican primary with 52.2% (1,289) against business manager Nicole Mitzel with 47.8% (1,180). 2,469 votes counted.