- Lead
- 8,103
- Total
- 22,090
- vs nation
- R+35.2
Delaware 21st State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 6,421
- Total
- 21,165
- vs nation
- R+34.8
- Lead
- 6,951
- Total
- 19,119
- vs nation
- R+38.4
- Lead
- 4,735
- Total
- 16,426
- vs nation
- R+32.7
- Lead
- 3,846
- Total
- 15,533
- vs nation
- R+32.0
- Lead
- 5,078
- Total
- 13,958
- vs nation
- R+33.9
- Lead
- 2,686
- Total
- 11,637
- vs nation
- R+23.6
- Lead
- 1,065
- Total
- 9,034
- vs nation
- R+20.3
Key facts
- 2024 presidential margin
- R+36.7MIT Election Lab
- Population
- 48,9792024 5-year
- Population density
- 168 / sq mi2024 5-year · TIGER/Line
- Land area
- 292 sq miTIGER/Line
- Median household income
- $66,6182024 5-year
- White (non-Hispanic)
- 65.3%2024 5-year
- Black
- 17.0%2024 5-year
- Hispanic / Latino
- 10.7%2024 5-year
- Peak Republican margin
- R+90.2 in 1952MIT Election Lab
- Most similar
- State Senate District 15, DE · twin score 91.1
presidential history
Party record book
Delaware 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
Grover Cleveland1884
49.7%
572 votes · R+0.7 · modeled estimate
Runner-up · Lyndon B. Johnson, 1964 · 46.6%
Republican
Dwight D. Eisenhower1952
94.7%
3,496 votes · R+90.2 · modeled estimate
Runner-up · Ronald Reagan, 1984 · 74.7%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
7,231votes
34.2% of the vote · R+30.3 · modeled estimate
Runner-up · Kamala Harris, 2024 · 6,857 votes
Republican
Donald Trump2024
14,960votes
67.7% of the vote · R+36.7 · modeled estimate
Runner-up · Donald Trump, 2020 · 13,652 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
John W. Davis1924
+1.9pts D vs U.S.
Place R+23.3 · U.S. R+25.2 · modeled estimate
Runner-up · James M. Cox, 1920 · −1.3 pts
Republican
Dwight D. Eisenhower1952
+79.5pts R vs U.S.
Place R+90.2 · U.S. R+10.8 · modeled estimate
Runner-up · Donald Trump, 2016 · +38.4 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.
| Year | Vote lead | Democratic | Republican | Total |
|---|---|---|---|---|
| 2020 | R | 42.4%9,388 | 55.7%12,313 | 22,121 |
| 2018 | R | 49.7%8,440 | 50.3%8,548 | 16,988 |
Delaware 21st State Senate District sits in the Mid-Atlantic. In 2024 it voted Republican.
Across the recorded series it reached a Republican high of 90.2 points in 1952. Between 2020 and 2024 the district moved 6.3 points toward the Republican candidate; the 2024 margin was 36.7 points.
A population of 48,979, a 65% non-Hispanic-white share, and a median household income of $66,618 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 15 and State Senate District 18.
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 →
Delaware 21st State Senate District. Akashic. https://akashic.app/sld-upper/10021/. Accessed May 20, 2026. License: CC BY 4.0.