- Lead
- 9,817
- Total
- 310,186
- vs nation
- D+4.6
Texas 21st State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 51,593
- Total
- 302,737
- vs nation
- D+12.6
- Lead
- 55,808
- Total
- 227,295
- vs nation
- D+22.5
- Lead
- 43,547
- Total
- 196,136
- vs nation
- D+18.3
- Lead
- 44,181
- Total
- 194,329
- vs nation
- D+15.5
- Lead
- 9,610
- Total
- 174,412
- vs nation
- D+8.0
- Lead
- 5,889
- Total
- 142,240
- vs nation
- D+3.6
- Lead
- 34,323
- Total
- 118,301
- vs nation
- D+20.5
Key facts
- 2024 presidential margin
- D+3.2MIT Election Lab
- Population
- 907,9422024 5-year
- Population density
- 55 / sq mi2024 5-year · TIGER/Line
- Land area
- 16,509 sq miTIGER/Line
- Median household income
- $69,4612024 5-year
- White (non-Hispanic)
- 23.5%2024 5-year
- Black
- 3.4%2024 5-year
- Hispanic / Latino
- 69.2%2024 5-year
- Peak Democratic margin
- D+80.6 in 1932MIT Election Lab
- Most similar
- State Senate District 19, TX · twin score 97.8
presidential history
Party record book
Texas 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. Roosevelt1932
90.2%
21,799 votes · D+80.6 · modeled estimate
Runner-up · Franklin D. Roosevelt, 1936 · 86.9%
Republican
Richard Nixon1972
49.5%
34,693 votes · D+0.8 · modeled estimate
Runner-up · Ronald Reagan, 1984 · 48.2%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
174,751votes
57.7% of the vote · D+17.0 · modeled estimate
Runner-up · Kamala Harris, 2024 · 158,205 votes
Republican
Donald Trump2024
148,388votes
47.8% of the vote · D+3.2 · modeled estimate
Runner-up · Donald Trump, 2020 · 123,158 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
+76.9pts D vs U.S.
Place D+51.7 · U.S. R+25.2 · modeled estimate
Runner-up · Franklin D. Roosevelt, 1932 · +62.9 pts
Republican
George W. Bush2000
−3.6pts R vs U.S.
Place D+4.1 · U.S. D+0.5 · modeled estimate
Runner-up · Donald Trump, 2024 · −4.6 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.
Its 2024 presidential margin of D+3.2 ranked among Texas's closest, against D+22.7 in 2008. No racial group formed a majority of its residents in the 2024 ACS 5-year, with Hispanic or Latino residents at 61.3%.
Across the recorded series it reached a Democratic high of 80.6 points in 1932. Between 2020 and 2024 the district moved 13.9 points toward the Republican candidate; the 2024 margin was 3.2 points.
A population of 907,942, a 24% non-Hispanic-white share, and a median household income of $69,461 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 19 and State Senate District 29.
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 →
Texas 21st State Senate District. Akashic. https://akashic.app/sld-upper/48021/. Accessed May 20, 2026. License: CC BY 4.0.