- Lead
- 2,768
- Total
- 25,656
- vs nation
- R+9.3
Massachusetts 21st State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 357
- Total
- 25,152
- vs nation
- R+5.9
- Lead
- 1,572
- Total
- 22,586
- vs nation
- R+9.1
- Lead
- 1,057
- Total
- 20,757
- vs nation
- R+8.9
- Lead
- 260
- Total
- 20,546
- vs nation
- R+8.5
- Lead
- 288
- Total
- 19,342
- vs nation
- D+3.9
- Lead
- 1,646
- Total
- 17,434
- vs nation
- D+8.9
- Lead
- 2,688
- Total
- 16,232
- vs nation
- D+8.0
Key facts
- 2024 presidential margin
- R+10.8MIT Election Lab
- Population
- 45,2612024 5-year
- Population density
- 584 / sq mi2024 5-year · TIGER/Line
- Land area
- 77.5 sq miTIGER/Line
- Median household income
- $107,3012024 5-year
- White (non-Hispanic)
- 85.9%2024 5-year
- Black
- 3.2%2024 5-year
- Hispanic / Latino
- 3.5%2024 5-year
- Peak Democratic margin
- D+36.1 in 1964MIT Election Lab
- Peak Republican margin
- R+65.7 in 1896MIT Election Lab
- Most similar
- 8th Plymouth District, MA · twin score 94.8
presidential history
Party record book
Massachusetts 21st State House 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
Lyndon B. Johnson1964
67.8%
8,151 votes · D+36.1 · modeled estimate
Runner-up · Hubert Humphrey, 1968 · 52.0%
Republican
William McKinley1896
79.6%
1,689 votes · R+65.7 · modeled estimate
Runner-up · Warren G. Harding, 1920 · 77.4%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
12,054votes
47.9% of the vote · R+1.4 · modeled estimate
Runner-up · Kamala Harris, 2024 · 11,223 votes
Republican
Donald Trump2024
13,991votes
54.5% of the vote · R+10.8 · modeled estimate
Runner-up · Donald Trump, 2020 · 12,411 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
Lyndon B. Johnson1964
+13.5pts D vs U.S.
Place D+36.1 · U.S. D+22.6 · modeled estimate
Runner-up · George McGovern, 1972 · +10.6 pts
Republican
William McKinley1896
+59.6pts R vs U.S.
Place R+65.7 · U.S. R+6.1 · modeled estimate
Runner-up · William McKinley, 1900 · +38.0 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 |
|---|---|---|---|---|
| 2024 | D | 66.5%13,791 | 33.5%6,952 | 20,743 |
| 2020 | D | 64.7%13,619 | 35.3%7,435 | 21,054 |
Massachusetts 21st State House District sits in New England. In 2024 it voted Republican.
Across the recorded series it reached a Democratic high of 36.1 points in 1964 and a Republican high of 65.7 points in 1896. Between 2020 and 2024 the district moved 9.4 points toward the Republican candidate; the 2024 margin was 10.8 points.
A population of 45,261, a 86% non-Hispanic-white share, and a median household income of $107,301 describe the district. The district's voting pattern over the last decade is most similar to that of 8th Plymouth District and 7th Plymouth District.
The state-house 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 →
Massachusetts 21st State House District. Akashic. https://akashic.app/sld-lower/25021/. Accessed May 20, 2026. License: CC BY 4.0.