2024
R+11.1marginDonald TrumpRep
279,534
54.2%
Kamala HarrisDem
222,115
43.1%
All other candidates
13,936
2.7%
515,585 ballots cast · 41.1 per 100 residents (2024 population estimate)
Residents1,254,213+16.6% since 2020 (+178,701 people)
Collin County
Texas·FIPS 48085·1,297,179 residents (2025 estimate)
2024 result
R+11.1
515,585 ballots cast
What happened: the county's margin each cycle, against the national result.
Lean vs. nation
R+9.9
How this county sits relative to the country in 2024, with the national environment removed.
Trend since 2000
+40.6 pts
Net movement of that lean across 7 cycles — toward Democrats.
Elasticity
1.42
Amplifies national swings — moves harder than the country.
Bellwether error
28.5
Average gap between this county's margin and the nation's.
Votes by candidate
7 cyclesCertified vote counts for each party's nominee, the combined total for everyone else on the ballot, the number of ballots cast, and how many people lived here at the time.
2020
R+4.3marginDonald TrumpRep
252,318
51.4%
Joe BidenDem
230,945
47.0%
All other candidates
7,593
1.5%
490,856 ballots cast · 45.6 per 100 residents (2020 population estimate)
Residents1,075,512+14.0% since 2016 (+131,770 people)
Measured across a change of Census vintage. The two series share no common year, so how far apart they sit cannot be measured — this change carries an unknown amount of revision on top of four years of real change.
2016
R+16.7marginDonald TrumpRep
201,014
55.6%
Hillary ClintonDem
140,624
38.9%
All other candidates
19,781
5.5%
361,419 ballots cast · 38.3 per 100 residents (2016 population estimate)
Residents943,742+13.0% since 2012 (+108,512 people)
2012
R+31.5marginMitt RomneyRep
196,888
65.0%
Barack ObamaDem
101,415
33.5%
All other candidates
4,518
1.5%
302,821 ballots cast · 36.3 per 100 residents (2012 population estimate)
Residents835,230+12.7% since 2008 (+93,966 people)
Measured across a change of Census vintage. Where the two vintages overlap, 96% of counties agree within 0.5%, so read this figure to about half a point and no finer.
2008
R+25.6marginJohn McCainRep
184,897
62.3%
Barack ObamaDem
109,047
36.8%
All other candidates
2,639
0.9%
296,583 ballots cast · 40.0 per 100 residents (2008 population estimate)
Residents741,264+20.0% since 2004 (+123,462 people)
2004
R+43.0marginGeorge W. BushRep
174,435
71.2%
John KerryDem
68,935
28.1%
All other candidates
1,784
0.7%
245,154 ballots cast · 39.7 per 100 residents (2004 population estimate)
Residents617,802+23.8% since 2000 (+118,684 people)
2000
R+48.6marginGeorge W. BushRep
128,179
73.1%
Al GoreDem
42,884
24.4%
All other candidates
4,357
2.5%
175,420 ballots cast · 35.1 per 100 residents (2000 population estimate)
Residents499,118
“All other candidates” is every remaining line on the presidential ballot combined — minor parties, independents and write-ins where the state reports them. Shares are of all ballots cast, so the three rows sum to 100%.
Ballots cast per 100 residents is not a turnout rate. It measures votes against every resident — children and non-citizens included — not against eligible or registered voters, which is what turnout means and which this site does not have a county-level figure for. It is shown only where an election year and a population estimate share the same year and describe the same territory; where the Census figure is stated on boundaries the vote was not cast on, the card says so and the ratio is withheld.
A change in residents is not a change in voters. The percentage beside each year is the change in resident population since the previous presidential election — everyone who lives here, including children and non-citizens. It is not turnout, not registration, and not the same quantity as the change in ballots cast. Population is measured on 1 July of the election year, four months before the vote, which is the closest an annual series gets to election day.
Population figures on this page come from 3 Census series: PEP intercensal county estimates, 2000–2010; PEP vintage 2019 county estimates, 2010–2019; PEP vintage 2025 county estimates, 2020–2025. The 2012 and 2020 figures are the first in a new series, so the change shown for those years is measured across a change of Census method as well as across four years. Each of those cards says so. Two figures drawn from different vintages are not two readings of one series.
Every cycle
| Year | Margin | Lean | Swing | Rel. swing | Votes | 3rd party |
|---|---|---|---|---|---|---|
| 2024 | R+11.1 | R+9.9 | -7.0 | -1.0 | 515,585 | 2.7% |
| 2020 | R+4.3 | R+8.9 | +13.3 | +10.9 | 490,856 | 1.6% |
| 2016 | R+16.7 | R+19.9 | +14.3 | +16.1 | 361,419 | 5.5% |
| 2012 | R+31.5 | R+36.0 | -6.2 | -2.8 | 302,821 | 1.5% |
| 2008 | R+25.6 | R+33.2 | +17.6 | +7.7 | 296,583 | 0.9% |
| 2004 | R+43.0 | R+40.9 | +6.5 | +9.6 | 245,154 | 0.7% |
| 2000 | R+48.6 | R+50.5 | — | — | 175,420 | 2.5% |
Margin is over all votes cast. Lean is the two-party margin minus the nation's — the county's own position with the national environment removed. Relative swing is the change in that lean. “Votes” is the number of ballots cast in the presidential contest, not a share of eligible voters.
Counties on a similar trajectory
Sources
Presidential returns from the MIT Election Data and Science Lab (County Presidential Returns 2000–2024, CC0). Geography and FIPS codes from the US Census Bureau (public domain). Where a state reports both a total and per-mode vote counts, the reported total is used.
Resident population from the US Census Bureau, Population Estimates Program (Vintage 2025), measured as of July 1, 2025. Resident population — all residents, including children and non-citizens. Not an electorate, and not comparable to a vote total as a turnout rate. Conclusions drawn from it are ours, not the Bureau's.
Population at each election is measured on 1 July of the election year and comes from the US Census Bureau's Population Estimates Program (public domain). The 2000–2024 span is covered by several separately estimated vintages of that programme rather than by one continuous series — the ones used on this page are named under the cycle cards, and every change measured across a boundary between them is marked there. Notes about territory changing hands come from this site's own change ledger and are only as complete as it is.