State legislatures › South Dakota Senate
South Dakota Senate District 12
2026 forecast · Updated October 22, 2026, 09:28 UTC
17% chance of a Democratic win · Joe Zweifel (D), Kari Shanard-Koenders (R)
District 12 leans Republican. Of its 5 neighbouring districts, 2 favour Democrats, 3 favour Republicans.
| Status | Forecast |
|---|---|
| Chance of a Democratic win | 17% |
| Likely margin (80% range) | R+19 to D+3, middle R+8 |
| Candidates | Joe Zweifel (D), Kari Shanard-Koenders (R) |
| Candidate list from | aggregator (The Ballot Brief) |
| Current member | Arch Beal |
How it has voted
On its current lines. Legislative contests and the top-of-ticket vote inside the district.
Who lives here
Census Bureau, American Community Survey 2019-2023.
| This district | South Dakota | ||
|---|---|---|---|
| Median household income | $66,466 | $72,421 | |
| Bachelor's degree or more (25+) | 44% | 31% | |
| Median age | 33 | 38 | |
| White (not Hispanic) | 84% | 80% | |
| Black | 4% | 2% | |
| Hispanic | 5% | 5% | |
| Asian | 2% | 1% | |
| Born abroad | 7% | 4% | |
| Jobs in manufacturing | 7% | 10% | |
| Jobs in farming or mining | 1% | 6% |
Initial version. This model was tested on every state legislative election from 1994 to 2024 before publication, forecasting each as if it had not happened. It beat the simple rule “the party that holds the seat keeps it”, and its chamber seat counts were off by 2.9 seats on average (target: under 3). Districts with no two-party race last time are read from their own presidential vote, a change tested in advance that cut their average error from 17 to 13 points. It missed one of its five accuracy targets: in 2024, the calmest year on record, its ranges were wider than they needed to be (92% of results fell inside its 80% ranges; target: at most 88%). Treat the ranges as cautious. The full test record and code.