Definition
The County Turnout Score is a predictive model that estimates the likelihood an individual will vote in their local county election, such as a county commissioner, sheriff, county clerk, or county ballot measure race. These models are custom-trained for each specific county where the county race is the top-of-ticket contest. Note that this score should NOT be used in federal or other statewide elections - in that case we would recommend using the appropriate statewide score (e.g. Off Year Statewide General Turnout Score for races occurring on Nov 4, 2025, or the Midterm General Turnout Score/ Presidential General Turnout Score for races occurring in 2026/2028, respectively). In jurisdictions where the County Turnout Score is unavailable (either because local vote history data is unavailable, or because the election is a special election, e.g.), you can use the Local Voter Score as an alternative.
Technical Details
The County Turnout Score was built in each county where Murmuration has sufficient vote history from previous similar elections and where county elections are not held concurrently with federal/statewide elections. The model was trained on the vote history and demographics of individuals in a given location, meaning the model for Montgomery County, Ohio will differ from the model for Nassau County, New York. This reflects both the different predictive power of model inputs across geographies and the different elections used as training targets. In each location, we identified a recent election held countywide and used it as the basis for labeling voters: those who voted are labeled as targets, and those who did not are labeled as non-targets.
The County Turnout Score ranges from 0–100, where an individual's specific score approximately corresponds to their likelihood of voting in an upcoming county election.
We validated the model’s accuracy using a held-out test set of 20% of the original sample. Among individuals with scores in the top 20% of the County Turnout Score, 67% voted in county elections, compared to 25% of the population at large. Thus by using this score for targeting, our partners are 168% more likely to reach voters in county elections than if they targeted at random.
Use Cases
As with turnout scores more generally, this score can be used in two broad ways:
- Persuasion/Name Recognition: Using the higher end of the County Turnout Score, organizations can focus outreach on individuals already likely to vote in upcoming county elections. This is particularly useful in the early stages of a campaign — especially where name recognition is low — to ensure resources are directed toward voters who are most likely to turn out.
- GOTV: Voters who fall in the middle to low range of the County Turnout Score distribution (say with scores of between 30 and 70) can be targeted for GOTV outreach. When used in this manner, the score should generally target known supporters of candidates or issues to ensure partners are communicating with the voters most likely to support their work.
Targeting Table
The table below shows the score values associated with each decile to help you more easily target using the County Turnout Score nationally. Note: as this score is built in each particular jurisdiction, these score cutoffs differ based on the turnout patterns specific to your local counties - so you can use these as a starting point, but should adjust the thresholds according to your desired universe size.
| To target the top… | Set the minimum score value as… |
| 10% | 80 |
| 20% | 55 |
| 30% | 33 |
| 40% | 16 |
| 50% | 7 |
| 60% | 3 |
| 70% | 1 |
| 80% | 1 |
| 90% | 0 |
| 100% | 0 |