424,692
Active registered voters
297
Precincts
265,393
Supervoters (62.49%)
5
Presidential cycles of results
Data as of September 22, 2026 · refreshed automatically from the official Colorado voter file
Jefferson County, CO has 424,692 active registered voters — 20.1% Republican, 26.4% Democratic, and 51.3% with no party affiliation, as of September 2026.
Party registration
Democratic 112,085 · Republican 85,162 · No Party Affiliation 217,866 · Other parties 9,579
Source: Motion51 voter database — official Colorado voter file
Most reliable-voting precincts
| # | Precinct | Active voters | Supervoters | Supervoter % |
|---|---|---|---|---|
| 1 | 7202430143 | 1,822 | 1,427 | 78.32% |
| 2 | 7222730256 | 1,567 | 1,217 | 77.66% |
| 3 | 7202730168 | 641 | 497 | 77.54% |
| 4 | 7042530052 | 929 | 720 | 77.5% |
| 5 | 7192430088 | 862 | 666 | 77.26% |
| 6 | 7042530048 | 1,755 | 1,351 | 76.98% |
| 7 | 7222330222 | 1,804 | 1,386 | 76.83% |
| 8 | 7202830209 | 1,453 | 1,107 | 76.19% |
| 9 | 7192430079 | 1,304 | 988 | 75.77% |
| 10 | 7202830207 | 952 | 717 | 75.32% |
Supervoters are active registered voters who cast a ballot in at least 3 of the last 4 November general elections (2018–2024). Percentages are precinct totals from the official state voter file — no individual voter information is shown. Precincts with fewer than 400 active voters are excluded.
Source: Motion51 voter database — official Colorado voter file
How Jefferson County voted for president
■ Democratic % ■ Republican % · 2024 total votes cast: 361,504
Election results are public records.
Source: Official county canvasses via MIT Election Data + Science Lab
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