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What are the top 5 most conservative counties in California by voter registration?
Executive Summary
The most conservative counties in California by registered Republicans vary by reporting date, but three small northeastern Sierra counties — Modoc, Lassen, and Amador — repeatedly appear at the top across official registration snapshots. Reports from October 2020 and October 2023 list Modoc and Lassen as the two counties with the highest Republican registration shares, while a November 2024 snapshot shifts rankings to put Lassen slightly ahead of Modoc and elevates Shasta and Tehama into the top five depending on the date and dataset used [1] [2] [3]. The variation reflects small-population county volatility and periodic updates in the California Secretary of State registration reports rather than a substantive realignment of statewide party geography.
1. How the headline lists differ — a quick scoreboard that matters
Comparing the listed “top five” sets shows a clear pattern of agreement on a small cluster of rural counties even as their order changes across snapshots. A 2020 registration report identifies Modoc, Lassen, Amador, Calaveras, and Plumas as the top five by Republican share [1]. A 2023 registration snapshot provides very similar names and percentages, again putting Modoc and Lassen at the summit with Republican shares above 44–55 percent [2]. By contrast, a November 2024 compilation of county party totals reorders those counties and lists Lassen, Modoc, Shasta, Tehama, and Amador among the highest Republican-registration counties, with Lassen appearing at the top with a substantially higher share in that snapshot [3]. These changes are consistent with reporting-date differences and small-sample effects in low-population counties rather than large statewide shifts.
2. Why small counties drive volatility in the rankings
The counties that dominate these lists are among California’s least populous, so small changes in a few dozen or a few hundred registrations can move a county up or down in percent-based rankings. Multiple reports note that the ten counties with the highest percent Republican registration are relatively small, with average populations under 100,000, which amplifies swings when voter rolls are updated or when registration drives target rural areas [4]. Official registration tallies are snapshots that reflect recent registration drives, removals for inactivity, and administrative updates; therefore, Modoc or Lassen can register dramatic percent changes across reporting dates even if absolute numbers change only modestly [1] [2]. This explains why lists from October 2020, October 2023, and November 2024 are consistent in naming the same general cluster but differ on precise ordering [1] [2] [3].
3. The persistent core: Modoc, Lassen, and Amador explain Republican concentration
Across the cited registration reports, Modoc and Lassen consistently show the highest Republican registration percentages, often exceeding the 50-percent threshold in earlier snapshots and staying well above county averages in later ones [1] [2] [3]. Amador also appears repeatedly in the top five, typically in the 44–49 percent Republican range across the 2020–2023 snapshots [1] [2]. These counties sit in California’s rural interior where party registration skews conservative relative to the statewide mix dominated by large urban counties. The consistency across multiple registration reports indicates a structural geographic pattern: smaller, rural Sierra and northern interior counties concentrate higher shares of registered Republicans, even as exact ranks shift with administrative updates [1] [2].
4. Methodology matters: registration snapshot vs. electoral performance
The lists discussed are based on registered-party affiliation percentages rather than voting outcomes or turnout; using registration as the metric favors areas with stable party enrollment rules and may not match election-day behavior or nonpartisan ballots. Sources used are registration reports and county-by-county party totals; they measure the share of registered voters who identify as Republican on specific report dates [1] [2] [3]. Analysts relying solely on registration risk overstating uniformity: some registered Republicans may cross-party vote in certain races, while independent or declining-party registrants can influence outcomes differently. Therefore, while Modoc, Lassen, and Amador top registration lists, electoral competitiveness requires comparing these registration shares with turnout and vote results from the corresponding election cycles [3].
5. What readers should take away and what’s still missing
The strongest, verifiable takeaway is that Modoc and Lassen are the perennial leaders in Republican registration share, with Amador commonly among the next highest counties; Calaveras, Plumas, Shasta, and Tehama appear near the top depending on the reporting date [1] [2] [3]. The remaining uncertainty stems from changing report dates and the sensitivity of percent-based rankings in low-population counties. For a definitive, up-to-the-minute list consult the California Secretary of State’s latest county registration report and compare consecutive monthly snapshots to observe trends rather than single-date rankings; the sources used here illustrate the pattern but differ by snapshot date [1] [2] [3].