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New Castle County

Delaware·FIPS 10003·588,026 residents (2025 estimate)

2024 result

D+32.6

275,917 ballots cast

What happened: the county's margin each cycle, against the national result.

D+50D+25EvenR+25R+502000200420082012201620202024D+23D+22D+40.6D+34.1D+29.5D+37.1D+32.6
This countyNational margin

Lean vs. nation

D+34.6

How this county sits relative to the country in 2024, with the national environment removed.

Trend since 2000

+11.5 pts

Net movement of that lean across 7 cycles — toward Democrats.

Elasticity

1.63

Amplifies national swings — moves harder than the country.

Bellwether error

29.8

Average gap between this county's margin and the nation's.

Votes by candidate

7 cycles

Certified 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.

2024

D+32.6margin
Kamala HarrisDem
180,700
65.5%
Donald TrumpRep
90,868
32.9%
All other candidates
4,349
1.6%

275,917 ballots cast · 47.1 per 100 residents (2024 population estimate)

Residents586,014+2.6% since 2020 (+15,073 people)

2020

D+37.1margin
Joe BidenDem
195,034
67.8%
Donald TrumpRep
88,364
30.7%
All other candidates
4,235
1.5%

287,633 ballots cast · 50.4 per 100 residents (2020 population estimate)

Residents570,941+2.9% since 2016 (+15,883 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+29.5margin
Hillary ClintonDem
162,919
62.1%
Donald TrumpRep
85,525
32.6%
All other candidates
13,947
5.3%

262,391 ballots cast · 47.3 per 100 residents (2016 population estimate)

Residents555,058+1.9% since 2012 (+10,210 people)

2012

D+34.1margin
Barack ObamaDem
167,082
66.3%
Mitt RomneyRep
81,230
32.2%
All other candidates
3,700
1.5%

252,012 ballots cast · 46.3 per 100 residents (2012 population estimate)

Residents544,848+2.0% since 2008 (+10,890 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+40.6margin
Barack ObamaDem
178,768
69.7%
John McCainRep
74,608
29.1%
All other candidates
3,041
1.2%

256,417 ballots cast · 48.0 per 100 residents (2008 population estimate)

Residents533,958+2.9% since 2004 (+15,014 people)

2004

D+22.0margin
John KerryDem
146,171
60.5%
George W. BushRep
93,070
38.5%
All other candidates
2,203
0.9%

241,444 ballots cast · 46.5 per 100 residents (2004 population estimate)

Residents518,944+3.4% since 2000 (+17,107 people)

2000

D+23.0margin
Al GoreDem
127,539
59.9%
George W. BushRep
78,587
36.9%
All other candidates
6,869
3.2%

212,995 ballots cast · 42.4 per 100 residents (2000 population estimate)

Residents501,837

“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

YearMarginLeanSwingRel. swingVotes3rd party
2024D+32.6D+34.6-4.6+1.5275,9171.6%
2020D+37.1D+33.1+6.5+4.2287,6331.5%
2016D+29.5D+28.9-3.4-1.6262,3915.3%
2012D+34.1D+30.6-6.5-3.2252,0121.5%
2008D+40.6D+33.7+18.9+9.1256,4171.2%
2004D+22.0D+24.7-1.6+1.6241,4440.9%
2000D+23.0D+23.1212,9953.2%

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.