Rock County, Wisconsin: Industrial Catholic Metro county. In 2024, voted D+7%. Republican peak: R+71 in 1920.
Key facts
- 2024 presidential margin
- D+7MIT Election Lab
- Political typology
- Industrial Catholic MetroAkashic typology
- Population
- 164,3502024 5-year
- Median household income
- $75,6732024 5-year
- White (non-Hispanic)
- 81.6%2024 5-year
- Black
- 4.7%2024 5-year
- Hispanic / Latino
- 10.1%2024 5-year
- Peak Democratic margin
- D+29 in 2008MIT Election Lab
- Peak Republican margin
- R+71 in 1920MIT Election Lab
- Most similar
- Lucas County, OH · similarity 0.99
2024 results by precinct
2024 precinct map of Rock CountyPrecinct-level 2024 presidential results for Rock County, with each precinct boundary colored by Democratic-vs-Republican margin.
—
Margin—
Turnout—
Harris +50Trump +50
Real precinct boundaries. Hover for vote totals.
presidential history
Presidential margin, 1876–2024
Democratic minus Republican, by election
| Year | Margin (D minus R) |
|---|---|
| 1876 | No data |
| 1880 | No data |
| 1884 | No data |
| 1888 | No data |
| 1892 | −16.6% |
| 1896 | −37.7% |
| 1900 | −43.7% |
| 1904 | −50.5% |
| 1908 | −39.3% |
| 1912 | −12.6% |
| 1916 | −26.1% |
| 1920 | −70.9% |
| 1924 | −54.9% |
| 1928 | −42.0% |
| 1932 | −14.0% |
| 1936 | +9.8% |
| 1940 | −6.9% |
| 1944 | −4.8% |
| 1948 | −2.7% |
| 1952 | −29.4% |
| 1956 | −35.2% |
| 1960 | −21.4% |
| 1964 | +16.2% |
| 1968 | −9.4% |
| 1972 | −17.8% |
| 1976 | −0.5% |
| 1980 | −10.2% |
| 1984 | −10.2% |
| 1988 | +2.4% |
| 1992 | +13.3% |
| 1996 | +20.5% |
| 2000 | +18.5% |
| 2004 | +16.7% |
| 2008 | +29.3% |
| 2012 | +23.2% |
| 2016 | +10.3% |
| 2020 | +11.2% |
| 2024 | +7.3% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| D | 46,642 | 40,218 | 88,310 | ||
| D | 46,658 | 37,138 | 85,360 | ||
| D | 39,339 | 31,493 | 76,074 | ||
| D | 49,219 | 30,517 | 80,690 | ||
| D | 50,529 | 27,364 | 79,169 | ||
| D | 46,598 | 33,151 | 80,479 | ||
| D | 40,472 | 27,467 | 70,404 | ||
| D | 32,450 | 20,096 | 60,320 | ||
| D | 31,154 | 21,942 | 69,025 | ||
| D | 29,576 | 28,178 | 58,188 | ||
| R | 26,433 | 32,491 | 59,334 | ||
| R | 24,740 | 30,960 | 61,182 | ||
| R | 28,048 | 28,325 | 57,762 | ||
| R | 21,033 | 30,361 | 52,319 | ||
| R | 20,567 | 25,229 | 49,493 | ||
| D | 28,257 | 20,372 | 48,684 | ||
| R | 19,194 | 29,675 | 48,945 | ||
| R | 13,834 | 28,980 | 42,987 | ||
| R | 15,183 | 27,837 | 43,065 | ||
| R | 16,150 | 17,068 | 33,692 | ||
| R | 16,766 | 18,477 | 35,376 | ||
| R | 17,543 | 20,141 | 37,898 | ||
| D | 17,991 | 14,693 | 33,729 | ||
| R | 12,612 | 16,825 | 30,008 | ||
| R | 8,726 | 21,497 | 30,384 | ||
| R | 1,453 | 14,815 | 24,320 | ||
| R | 2,447 | 16,152 | 19,337 | ||
| R | 4,015 | 7,011 | 11,477 | ||
| R | 3,032 | 4,276 | 9,895 | ||
| R | 3,227 | 7,839 | 11,734 | ||
| R | 2,348 | 7,972 | 11,127 | ||
| R | 3,094 | 8,249 | 11,790 | ||
| R | 3,655 | 8,282 | 12,277 | ||
| R | 4,231 | 6,052 | 10,956 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
31.6%
Irish
13.0%
English
9.9%
American
5.5%
Polish
3.3%
Italian
2.9%
French
1.8%
African American
3.8%
Multiple ancestry combinations reported; no single grouping above 1%.
American Indian, Alaska Native, Native Hawaiian, and Pacific Islander combined.
Source · American Community Survey 5-year estimates, 2024 release. Hispanic/Latino is an ethnicity that overlaps the race categories, so these shares can total more than 100%. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
2024 ACS
Age distribution by sex
Median age: 40.3 in this county, 39.1 nationally
Male
Age
Female
85+
75–84
65–74
55–64
45–54
35–44
25–34
18–24
5–17
<5
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Median household income
Inflation-adjusted dollars
$75,673
Rock County ranks in the top 25% of US counties.
Rock County$75,673
Wisconsin$77,485
United States$80,734
Rock County ranks in the top 25% of US counties by median household income.
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Poverty rate
All persons below federal poverty line
9.3%
Child poverty is below the national average.
Children under 1812.9%
Working age (18–64)7.8%
Seniors (65+)12.2%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
91.2%
speak English only
Spanish7.2%
Other Indo-European0.8%
Asian & Pacific Islander0.7%
Other languages0.1%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 61.7% of residents not counted as adherents by any reporting body.
Rock County anchors south-central Wisconsin around Janesville, a former GM factory town whose blue-collar workforce has made it a consistent but narrowing Democratic margin county in statewide races.
Its margins are typically close. The Democratic margin reached twenty-nine points in 2008; the Republican margin reached seventy-one points in 1920. Between 2020 and 2024 the county moved four points toward the Republican candidate; the 2024 margin was seven points.
Its demographics sit near national norms: a 82% non-Hispanic-white share, a median household income of $75,673, and a 9% poverty rate. The county's voting pattern over the last decade is most similar to that of Lucas County and Iowa County.
Most similar counties
Compare two places, side by side
Twelve curated comparisons line up election history, demographics, and the divergence story for two places at a glance. Browse all comparisons →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Rock County, Wisconsin. Akashic. https://akashic.app/county/55105/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
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Frequently asked questions
How did Rock County, Wisconsin vote in 2024?
In 2024, Rock County, Wisconsin voted Democratic by 7.3 points (D+7), carried by the Democratic candidate. Out of 88,310 votes cast, 46,642 went Democratic and 40,218 went Republican.
What is Rock County, Wisconsin's political typology?
Akashic places Rock County, Wisconsin in the "Industrial Catholic Metro" typology — Mid-size industrial metros with Catholic ethnic roots — among the most competitive, swing-prone ground in the country. The typology is a data-driven cluster built from vote share, vote swing, race and ethnicity, income, language spoken at home, religion, and ancestry. Across 38 elections in the dataset, the county has voted Democratic 12 times, Republican 22 times, and other 0 times.
When did Rock County, Wisconsin last vote Republican?
The most recent presidential election in which Rock County, Wisconsin voted Republican was 1984.
How many people live in Rock County, Wisconsin?
Rock County, Wisconsin has a population of 164,350 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Rock County, Wisconsin?
Median household income in Rock County, Wisconsin is $75,673 — below the national median of $80,734. The Wisconsin state median is $77,485.
What is the political history of Rock County, Wisconsin?
Akashic tracks 38 presidential elections in Rock County, Wisconsin from 1876 to 2024. Of those, 12 went Democratic and 22 went Republican. The county's typology — "Industrial Catholic Metro" — captures where that record, its demographics, and its recent swing place it among American communities.