Keep Factually independent
Whether you agree or disagree with our analysis, these conversations matter for democracy. We don't take money from political groups - even a $5 donation helps us keep it that way.
Fact check: Which California counties had the highest Republican voter turnout in 2020?
Executive summary
California’s publicly available precinct and county returns from the 2020 general election show that some coastal and small-to-medium sized counties recorded the highest overall voter turnout, but Republican-specific turnout by share of registered Republicans is not uniformly reported in the articles provided. Multiple 2020-era county turnout reports cite Sonoma (≈90.49%) and Marin (≈90.25%) as among the highest overall turnout counties, while later precinct-level analyses highlight where Trump gained votes in 2020 without producing a clean, ranked list of counties where Republicans specifically had the highest turnout [1] [2] [3].
1. What the original claims said — “Highest Republican turnout” versus “highest overall turnout”
The materials supplied mix two distinct claims: one about overall registered voter turnout and another about Republican turnout specifically. News pieces from December 2020 present Sonoma and Marin counties as having the highest overall participation rates in the November 2020 election (Sonoma 90.49%, Marin 90.25%), framing them as among California’s most engaged electorates [1]. Those pieces do not directly measure turnout among only Republican voters, and later analytical work warns against equating high overall turnout with high partisan turnout without precinct-level party breakdowns [3].
2. Where the reporting is specific — Sonoma and Marin as high-turnout counties
Contemporaneous county reports and local coverage emphasize Sonoma and Marin because county election offices reported unusually high proportions of registered voters casting ballots in 2020, a mail-ballot-heavy election year [1]. These articles use Secretary of State and county certifications and focus on turnout percentages of registered voters rather than vote share for a given party. The reporting is factual about those percentages, but it does not translate those numbers into a categorical statement that Republicans had the highest turnout there, a distinction the sources do not support [1].
3. What later precinct-level studies add — where Trump gained ground but not a ranked Republican-turnout list
A deeper, more recent data release provides precinct-level vote tallies that allow analysts to see where Trump made gains in 2020 relative to 2016, and where Republican vote shares moved, but those datasets are analytical and require processing to produce a county-by-county ranking of Republican turnout among registered Republicans [3]. The June 2025 analysis notes that detailed precinct data exists statewide, enabling researchers to compute Republican turnout metrics, yet the article itself stops short of publishing a simple “top counties for Republican turnout” list [3].
4. Conflicting or incomplete interpretations in the sources
One set of sources is explicit about overall turnout rates and uses Secretary of State statistics; another set notes Republican vote-share increases without linking those changes to Republican registered-voter turnout levels by county [1] [4] [3]. This produces an interpretive gap: high county turnout does not necessarily mean high turnout among Republican registrants, especially in heavily Democratic counties with large numbers of non-Republican voters. The sources show evidence of both phenomena but do not reconcile them into a single factual answer [4] [1].
5. How to get the definitive answer — precinct-level and registration-weighted analysis
The only way to definitively rank counties by Republican turnout in 2020 is to combine precinct-level vote counts with voter registration by party as of the election and compute turnout among Republican registrants. The June 2025 precinct data release makes such a computation possible, and county or state election offices hold the registration snapshots necessary to perform it. The sources point to the available data but show no published, authoritative county ranking derived that way [3].
6. Potential agendas and reporting emphases to watch for
Local outlets highlighting high overall turnout often frame it as civic engagement and may emphasize cross-partisan turnout for community-validating narratives [1]. Political analyses focused on where Trump gained ground emphasize vote-share shifts and may be used to argue for Republican momentum or Democratic vulnerabilities; those analyses are selective about geographic scales and can conflate vote share gains with turnout among partisans [4] [5] [3]. Readers should note these differing emphases when interpreting headlines.
7. Short answer and recommended next steps for a definitive list
Short answer: based on the supplied reporting, Sonoma and Marin top lists for overall registered-voter turnout in 2020, but the sources do not provide a validated, statewide ranking of counties by Republican-specific turnout. To produce that definitive ranking, combine the Secretary of State’s precinct-level 2020 returns with county-level voter registration by party as of November 2020 and calculate turnout among registered Republicans — a task the June 2025 dataset enables but the articles do not complete [1] [3].