Nielson Brothers Polling
8 scored general-election polls (2014–2020) , each measured against the certified result. How to read these numbers: methodology.
Record by cycle
| Cycle | Polls | Avg. Error | Lean | Winner Called |
|---|---|---|---|---|
| 2020 | 2 | 12.8 pts | D+12.8 | 100% |
| 2016 | 3 | 19.6 pts | D+19.6 | 100% |
| 2014 | 3 | 14.1 pts | D+14.1 | 100% |
Every scored poll
| Date | Race | Poll Margin | Actual | Error | Called It |
|---|---|---|---|---|---|
| 2020-10-26 | SD Senate | R+17.0 | R+31.5 | 14.5 | ✓ |
| 2020-10-26 | SD President | R+15.0 | R+26.2 | 11.2 | ✓ |
| 2016-10-25 | SD-1 House | R+10.0 | R+28.2 | 18.2 | ✓ |
| 2016-10-25 | SD President | R+14.0 | R+29.8 | 15.8 | ✓ |
| 2016-10-25 | SD Senate | R+19.0 | R+43.7 | 24.7 | ✓ |
| 2014-09-23 | SD-1 House | R+18.0 | R+33.1 | 15.1 | ✓ |
| 2014-09-23 | SD Governor | R+25.0 | R+45.0 | 20.0 | ✓ |
| 2014-09-23 | SD Senate | R+13.7 | R+20.9 | 7.2 | ✓ |
Margins shown as party lead (D+/R+); for non-D-vs-R matchups the margin is first-listed candidate minus second. Historical scored-poll data for cycles through 2023 from FiveThirtyEight's pollster-ratings dataset (CC-BY-4.0); 2024 scored by PollingSource. This record never changes what enters the PollingSource average.