- Lead
- 2,627
- Total
- 71,591
- vs nation
- D+5.1
Colorado 21st State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 10,677
- Total
- 71,674
- vs nation
- D+10.4
- Lead
- 4,899
- Total
- 57,536
- vs nation
- D+6.4
- Lead
- 8,321
- Total
- 53,007
- vs nation
- D+11.8
- Lead
- 8,369
- Total
- 48,140
- vs nation
- D+10.1
- Lead
- 492
- Total
- 41,079
- vs nation
- D+3.7
- Lead
- 1,359
- Total
- 32,591
- vs nation
- D+3.7
- Lead
- 2,754
- Total
- 28,301
- vs nation
- D+1.2
Key facts
- 2024 presidential margin
- D+3.7MIT Election Lab
- Population
- 168,4132024 5-year
- Population density
- 123 / sq mi2024 5-year · TIGER/Line
- Land area
- 1,374 sq miTIGER/Line
- Median household income
- $93,0862024 5-year
- White (non-Hispanic)
- 41.2%2024 5-year
- Black
- 2.5%2024 5-year
- Hispanic / Latino
- 49.2%2024 5-year
- Peak Democratic margin
- D+38.9 in 1916MIT Election Lab
- Peak Republican margin
- R+97.2 in 1880MIT Election Lab
- Most similar
- State Senate District 24, CO · twin score 91.7
presidential history
Party record book
Colorado 21st State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 (partial returns from 1880) · 37 presidential cycles · 37 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
68.8%
10,466 votes · D+38.0 · modeled estimate
Runner-up · Woodrow Wilson, 1916 · 68.0%
Republican
James A. Garfield1880
98.6%
70 votes · R+97.2 · modeled estimate
Runner-up · James G. Blaine, 1884 · 98.5%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
40,242votes
56.1% of the vote · D+14.9 · modeled estimate
Runner-up · Kamala Harris, 2024 · 36,162 votes
Republican
Donald Trump2024
33,535votes
46.8% of the vote · D+3.7 · modeled estimate
Runner-up · Donald Trump, 2020 · 29,565 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
Woodrow Wilson1916
+35.7pts D vs U.S.
Place D+38.9 · U.S. D+3.1 · modeled estimate
Runner-up · Alton B. Parker, 1904 · +24.5 pts
Republican
William McKinley1900
+64.0pts R vs U.S.
Place R+71.5 · U.S. R+7.5 · modeled estimate
Runner-up · Benjamin Harrison, 1892 · +63.8 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 | 55.8%38,694 | 44.2%30,623 | 69,317 |
| 2020 | D | 58.4%39,024 | 41.6%27,817 | 66,841 |
Colorado 21st State Senate District sits in the Rocky Mountain West. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 38.9 points in 1916 and a Republican high of 97.2 points in 1880. Between 2020 and 2024 the district moved 11.2 points toward the Republican candidate; the 2024 margin was 3.7 points.
A population of 168,413, a 41% non-Hispanic-white share, and a median household income of $93,086 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 24 and State Senate District 13.
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 →
Colorado 21st State Senate District. Akashic. https://akashic.app/sld-upper/08021/. Accessed May 20, 2026. License: CC BY 4.0.