Voter file loaded July 20, 2026 · figures are from that file, held as a fixed record
Jefferson County, Idaho has 17,426 active registered voters — 79.8% Republican, 3.2% Democratic, and 0.0% with no party affiliation, as of July 2026.
Party registration
Most reliable-voting precincts
| # | Precinct | Active voters | Supervoters | Supervoter % |
|---|---|---|---|---|
| 1 | 021 | 494 | 267 | 54.05% |
| 2 | 004 | 829 | 446 | 53.8% |
| 3 | 009 | 864 | 434 | 50.23% |
| 4 | 006 | 922 | 433 | 46.96% |
| 5 | 018 | 797 | 366 | 45.92% |
| 6 | 007 | 915 | 408 | 44.59% |
| 7 | 019 | 1,215 | 527 | 43.37% |
| 8 | 017 | 1,029 | 445 | 43.25% |
| 9 | 002 | 1,130 | 481 | 42.57% |
| 10 | 008 | 456 | 193 | 42.32% |
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.
How Jefferson County voted for president
Election results are public records.
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