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What are the most republican counties in Idaho?
Executive Summary
The available analyses point to two complementary ways of defining “most Republican” in Idaho: by raw Republican registration totals and by Republican vote share in recent elections. Absolute registration counts from a 2020 snapshot list Ada, Canyon, Kootenai, Bonneville and Twin Falls among the top counties by Republican registrants, while 2020 election returns show Kootenai, Canyon, Twin Falls and Bonneville producing the highest Republican vote shares — with Ada showing large raw votes but a lower Republican percentage [1] [2]. Recent reporting and datasets note many small cities with overwhelmingly conservative electorates that sit in similarly Republican counties, but no single provided source offers a definitive, up‑to‑date ranked list by percentage beyond 2020 snapshots and local analyses [3] [4].
1. What researchers claimed loudly — conflicting metrics produce different answers
Analysts using the voter registration totals declared a top‑five list based on the number of registered Republicans, giving Ada County the largest Republican cohort by raw numbers followed by Canyon, Kootenai, Bonneville and Twin Falls in a January 24, 2020 snapshot; that list emphasizes population size and organizational strength rather than partisan intensity [1]. Conversely, examination of 2020 general election results focuses on vote shares and identifies Kootenai, Canyon, Twin Falls and Bonneville as counties where Republican candidates won their largest percentages, signaling deeper Republican intensity even where absolute numbers are smaller; Ada appears as high in raw votes but far less dominant by percentage [2]. Both metrics are valid but answer different questions: who has the most Republican voters versus where Republicans dominate electorally.
2. Why raw counts and percentages diverge — a crucial statistical reality
Raw registration totals correlate with population and urbanization: Ada County contains Boise and a much larger voter base, so even a mixed electorate produces a large Republican headcount; that makes Ada large in absolute terms but not the most Republican by share [1] [2]. Rural counties with smaller populations can show higher Republican percentages on election day because Democratic voters are scarce; thus counties like Kootenai, Canyon, Twin Falls and Bonneville return far higher Republican vote shares despite lower absolute totals than Ada [2]. This divergence matters for policy and politics: campaign resource allocation uses both measures differently — absolute votes for turnout strategies and percentage margins for identifying safe turf or swing potential [4].
3. Local reporting paints a picture of conservative pockets — cities point to county patterns
Local reporting that identified the “20 most conservative places” in Idaho provides a complementary lens by locating individual cities where Republican, Constitution and Libertarian voters outnumber Democrats by roughly 10‑to‑1; those cities (for example, Rexburg, Rigby, Preston, Sugar City and others) sit in counties such as Madison, Jefferson, Franklin and Fremont, indicating additional Republican strongholds beyond the big five counties named in registration and election totals [3]. Mapping these conservative cities to their counties shows that several smaller rural counties also register among the state’s most Republican communities, a pattern invisible if one looks only at high‑population counties [3].
4. Limitations in the dataset and the need for updated measurements
The materials provided include a 2020 registration snapshot and 2020 election returns plus later commentary and dashboards without explicit county‑by‑county percentage rankings after 2020; they do not deliver a single authoritative, post‑2020 ranked list of counties by Republican share [1] [2] [4]. State election dashboards and the Secretary of State’s election statistics pages are cited as sources that can be queried for up‑to‑date registration and election percentages; those tools are the next step if you need a current ranking because partisan geography can shift with migration, new registrations, and turnout changes since 2020 [4] [5]. Any definitive claim about “most Republican counties” should specify the metric (absolute registrations vs. percent Republican vote) and the date.
5. Bottom line — reconciled answer and how to use it
If “most Republican” is defined by highest Republican vote share in recent major contests, the 2020 election returns point to Kootenai, Canyon, Twin Falls and Bonneville as the strongest counties for Republican candidates, with Ada producing large raw Republican vote totals but a smaller percentage advantage [2]. If the definition is largest number of registered Republicans, a 2020 registration snapshot lists Ada, Canyon, Kootenai, Bonneville and Twin Falls as the top five by count [1]. For a current, precise ranking by either metric, consult the Idaho Secretary of State’s voter registration and county election results dashboards and specify whether you require absolute numbers or percentage margins [4] [5].