- Lead
- 1,231
- Total
- 100,084
- vs nation
- D+2.7
Wisconsin 21st State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 2,304
- Total
- 99,089
- vs nation
- R+2.1
- Lead
- 1,102
- Total
- 89,850
- vs nation
- R+3.3
- Lead
- 136
- Total
- 100,683
- vs nation
- R+3.7
- Lead
- 1,808
- Total
- 97,661
- vs nation
- R+5.4
- Lead
- 11,144
- Total
- 101,829
- vs nation
- R+8.5
- Lead
- 11,098
- Total
- 91,458
- vs nation
- R+12.7
- Lead
- 1,046
- Total
- 77,709
- vs nation
- R+9.9
Key facts
- 2024 presidential margin
- D+1.2MIT Election Lab
- Population
- 179,1692024 5-year
- Population density
- 1,221 / sq mi2024 5-year · TIGER/Line
- Land area
- 147 sq miTIGER/Line
- Median household income
- $77,8012024 5-year
- White (non-Hispanic)
- 69.2%2024 5-year
- Black
- 9.3%2024 5-year
- Hispanic / Latino
- 13.6%2024 5-year
- Peak Democratic margin
- D+27.4 in 1936MIT Election Lab
- Peak Republican margin
- R+55.2 in 1920MIT Election Lab
- Most similar
- State Senate District 7, WI · twin score 82.7
presidential history
Party record book
Wisconsin 21st State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 (partial returns from 1876) · 38 presidential cycles · 38 with a vote-share denominator · 34 with a national benchmark
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Franklin D. Roosevelt1936
59.9%
28,083 votes · D+27.4 · modeled estimate
Runner-up · Franklin D. Roosevelt, 1932 · 51.8%
Republican
Dwight D. Eisenhower1956
70.5%
58,077 votes · R+41.5 · modeled estimate
Runner-up · William McKinley, 1896 · 69.1%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
49,957votes
50.4% of the vote · D+2.3 · modeled estimate
Runner-up · Barack Obama, 2012 · 49,854 votes
Republican
Dwight D. Eisenhower1956
58,077votes
70.5% of the vote · R+41.5 · modeled estimate
Runner-up · Dwight D. Eisenhower, 1952 · 56,066 votes
Best relative to the U.S.
This Place’s margin against the national margin in the same election — positive when it leaned toward the party more than the country did.
Democratic
Franklin D. Roosevelt1936
+3.2pts D vs U.S.
Place D+27.4 · U.S. D+24.3 · modeled estimate
Runner-up · Kamala Harris, 2024 · +2.7 pts
Republican
William McKinley1896
+34.5pts R vs U.S.
Place R+40.6 · U.S. R+6.1 · modeled estimate
Runner-up · William McKinley, 1900 · +31.9 pts
Current officeholders
State legislative officeholder from OpenStates nightly current-legislator data.
Senate and governor results are in the Office selector at the top of this page.
U.S. House
Each row is a county-allocated estimate of U.S. House votes for this district — county returns apportioned onto its boundary, not precinct-counted. “Vote lead” is the estimated local lead here, not necessarily the winner of the full contest.
Wisconsin 21st State Senate District sits in the Upper Midwest. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 27.4 points in 1936 and a Republican high of 55.2 points in 1920. Between 2020 and 2024 the district moved 1.1 points toward the Republican candidate; the 2024 margin was 1.2 points.
A population of 179,169, a 69% non-Hispanic-white share, and a median household income of $77,801 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 7 and State Senate District 5.
The state-senate districts 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.
District research tools
Open the source-auditable district brief for electoral baseline, electorate, current-cycle coverage, geography, official dates, and methodology. Open campaign intelligence report → · Browse all comparisons →
Wisconsin 21st State Senate District. Akashic. https://akashic.app/sld-upper/55021/. Accessed May 20, 2026. License: CC BY 4.0.