2024
D+13.1marginKamala HarrisDem
251,164
55.0%
Donald TrumpRep
191,243
41.9%
All other candidates
14,475
3.2%
456,882 ballots cast · 49.0 per 100 residents (2024 population estimate)
Residents932,651+0.1% since 2020 (+1,178 people)
DuPage County
Illinois·FIPS 17043·934,298 residents (2025 estimate)
2024 result
D+13.1
456,882 ballots cast
What happened: the county's margin each cycle, against the national result.
Lean vs. nation
D+15.1
How this county sits relative to the country in 2024, with the national environment removed.
Trend since 2000
+29.4 pts
Net movement of that lean across 7 cycles — toward Democrats.
Elasticity
1.65
Amplifies national swings — moves harder than the country.
Bellwether error
10.1
Average gap between this county's margin and the nation's.
3 consecutive cycles moving toward Democrats relative to the nation.
Flipped 1 time since 2000 — 2008 to D
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
D+18.1marginJoe BidenDem
281,222
58.0%
Donald TrumpRep
193,611
39.9%
All other candidates
10,271
2.1%
485,104 ballots cast · 52.1 per 100 residents (2020 population estimate)
Residents931,473under 0.1% since 2016 (+217 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
D+14.5marginHillary ClintonDem
228,622
53.3%
Donald TrumpRep
166,415
38.8%
All other candidates
33,732
7.9%
428,769 ballots cast · 46.0 per 100 residents (2016 population estimate)
Residents931,256+0.3% since 2012 (+2,590 people)
2012
D+1.1marginBarack ObamaDem
199,460
49.7%
Mitt RomneyRep
195,046
48.6%
All other candidates
6,573
1.6%
401,079 ballots cast · 43.2 per 100 residents (2012 population estimate)
Residents928,666+2.1% since 2008 (+18,868 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
D+10.8marginBarack ObamaDem
228,698
54.7%
John McCainRep
183,626
43.9%
All other candidates
5,649
1.4%
417,973 ballots cast · 45.9 per 100 residents (2008 population estimate)
Residents909,798−0.5% since 2004 (−4,142 people)
2004
R+9.6marginGeorge W. BushRep
218,902
54.4%
John KerryDem
180,097
44.8%
All other candidates
3,447
0.9%
402,446 ballots cast · 44.0 per 100 residents (2004 population estimate)
Residents913,940+0.8% since 2000 (+7,656 people)
2000
R+13.3marginGeorge W. BushRep
201,037
55.2%
Al GoreDem
152,550
41.9%
All other candidates
10,775
3.0%
364,362 ballots cast · 40.2 per 100 residents (2000 population estimate)
Residents906,284
“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 | D+13.1 | D+15.1 | -4.9 | +1.1 | 456,882 | 3.2% |
| 2020 | D+18.1 | D+13.9 | +2.7 | +0.4 | 485,104 | 2.1% |
| 2016 | D+14.5 | D+13.5 | +14.6 | +16.4 | 428,769 | 7.9% |
| 2012 | D+1.1 | R+2.9 | -9.8 | -6.5 | 401,079 | 1.6% |
| 2008 | D+10.8 | D+3.6 | +20.7 | +10.8 | 417,973 | 1.4% |
| 2004 | R+9.6 | R+7.2 | +4.0 | +7.1 | 402,446 | 0.9% |
| 2000 | R+13.3 | R+14.3 | — | — | 364,362 | 3.0% |
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.