Grundy County, Iowa
Precinct data
Results by precinct
7 precincts · 7,131 votes
Precinct boundaries and identifiers are cycle-specific. This table does not join rows across years without a validated crosswalk.
| Precinct -P6P6 | 395 | 1,042 | 27 | 1,464 | 27.0% | 71.2% | R+44.2 |
|---|---|---|---|---|---|---|---|
| Precinct -P7P7 | 473 | 920 | 18 | 1,411 | 33.5% | 65.2% | R+31.7 |
| Precinct -P5P5 | 461 | 889 | 22 | 1,372 | 33.6% | 64.8% | R+31.2 |
| Precinct -P1P1 | 295 | 668 | 19 | 982 | 30.0% | 68.0% | R+38.0 |
| Precinct -P3P3 | 148 | 718 | 18 | 884 | 16.7% | 81.2% | R+64.5 |
| Precinct -P4P4 | 124 | 464 | 4 | 592 | 20.9% | 78.4% | R+57.4 |
| Precinct -P2P2 | 123 | 297 | 6 | 426 | 28.9% | 69.7% | R+40.8 |
Presidential margin, 1892–2024
Democratic minus Republican, by election
| Year | Margin (D minus R) |
|---|---|
| 1892 | −0.7% |
| 1896 | −21.9% |
| 1900 | −25.1% |
| 1904 | −35.7% |
| 1908 | −25.1% |
| 1912 | +23.5% |
| 1916 | −35.1% |
| 1920 | −72.7% |
| 1924 | −47.1% |
| 1928 | −38.6% |
| 1932 | +20.2% |
| 1936 | +18.8% |
| 1940 | −17.4% |
| 1944 | −24.6% |
| 1948 | −14.3% |
| 1952 | −58.3% |
| 1956 | −44.0% |
| 1960 | −39.3% |
| 1964 | +5.4% |
| 1968 | −46.7% |
| 1972 | −43.2% |
| 1976 | −26.5% |
| 1980 | −39.5% |
| 1984 | −40.1% |
| 1988 | −21.5% |
| 1992 | −20.5% |
| 1996 | −10.7% |
| 2000 | −28.0% |
| 2004 | −29.8% |
| 2008 | −16.9% |
| 2012 | −22.7% |
| 2016 | −38.5% |
| 2020 | −37.4% |
| 2024 | −41.7% |
U.S. Senate
| Year | Won | Democratic | Republican | Total |
|---|---|---|---|---|
| 2022 | R | 27.2%1,462 | 72.8%3,909 | 5,371 |
| 2020 | R | 29.4%2,120 | 67.9%4,900 | 7,212 |
Registered voters
By party of registration, over time
Registration leans Republican; the presidential vote runs 6.6 points more Democratic.
| Year | Total registered | Democratic | Republican | Unaffiliated | Other |
|---|---|---|---|---|---|
| 2008 | 9,085 | 1,721 | 4,113 | 3,250 | 1 |
| 2010 | 9,044 | 1,631 | 4,119 | 3,288 | 6 |
| 2012 | 9,088 | 1,562 | 4,268 | 3,246 | 12 |
| 2014 | 8,970 | 1,487 | 4,180 | 3,286 | 17 |
| 2016 | 9,055 | 1,493 | 4,251 | 3,285 | 26 |
| 2018 | 8,926 | 1,493 | 4,082 | 3,300 | 51 |
| 2020 | 9,067 | 1,767 | 4,475 | 2,773 | 52 |
| 2022 | 9,098 | 1,649 | 4,545 | 2,851 | 53 |
| 2024 | 9,134 | 1,496 | 4,699 | 2,869 | 70 |
Who moves in and out
Net migration over time, and who arrivals are — where they came from and what those places vote
−19 net domestic migration · 2025
Net −141 over 2011–2025 · gain loss
Arrivals reported $62,130 in average income, against $98,840 for residents who stayed — 37% lower. (IRS SOI, 2022–23)
The places arrivals came from lean R+14.9 on average — 27 points more Democratic-leaning than Grundy County, IA itself (R+41.7).
Where arrivals came from lean of each source
- Black Hawk County, IA91D+1.2
- Marshall County, IA29R+15.5
- Hardin County, IA25R+38.3
- Tama County, IA21R+26.8
- Butler County, IA20R+45.2
Where departures went households, 2022–23
- Black Hawk County, IA113
- Marshall County, IA24
Migration is one input to a place’s political change, not its cause — a shift can also come from residents changing their minds, generational turnover, or turnout. These figures describe the places people moved between; they do not measure how any mover voted.
| Year | Net domestic migration |
|---|---|
| 2011 | +6 |
| 2012 | −54 |
| 2013 | −114 |
| 2014 | +48 |
| 2015 | +36 |
| 2016 | −107 |
| 2017 | +42 |
| 2018 | −19 |
| 2019 | −29 |
| 2021 | +54 |
| 2022 | +9 |
| 2023 | +33 |
| 2024 | −27 |
| 2025 | −19 |
Grundy County's flat, productive farmland anchors an electorate that has shifted decisively rightward over two decades, delivering R+41.7 in 2024 — among the widest presidential margins of any county in the state.
Across the recorded series it reached a Democratic high of 23.5 points in 1912 and a Republican high of 72.7 points in 1920. Between 2020 and 2024 the county moved 4.3 points toward the Republican candidate; the 2024 margin was 41.7 points.
A population of 12,384, a 95% non-Hispanic-white share, and a median household income of $87,205 describe the county. The county's voting pattern over the last decade is most similar to that of Turner County and Otoe County.
The counties whose fingerprint — 2000–2024 trajectory, demographics, ancestry, religion — sits closest to this one, and why.
Twin score (0–100) = weighted cosine between tier-standardized fingerprints: presidential margins 2000–2024 with 12-yr trend and elasticity, ACS income, age, education, population and race, top reported ancestries, and religious adherence — chips name the closest-shared dimensions and the widest gap. Re-weight the groups in the twins explorer.
Browse places by community — income, education, race & ethnicity, language — all community cuts →
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 →
Grundy County, Iowa. Akashic. https://akashic.app/county/19075/. Accessed May 20, 2026. License: CC BY 4.0.