County record · fips 19101 · Iowa
JeffersonIA
Republican ×3 since 2016all 40 elections, 1868–2024
The Long Record
40 elections against the Iowa and national vote
2024 result
R+6.9
won by Republicans
Record since first cycle
7–33
Dem–Rep two-party wins
Voted with the winner
28/40
70% of its elections
Closest election
1988
R+0.3
this countyIowanational (official)dot colour = two-party winner · hollow = tie or unknown total · click a dot to open that election
The Biggest Swings
Cycle-over-cycle change in the two-party margin, in points
| Election | Swing | Toward |
|---|---|---|
| 1932 | +54.7 pts | Democrats |
| 1964 | +48.0 pts | Democrats |
| 1968 | -46.3 pts | Republicans |
| 1920 | -40.6 pts | Republicans |
| 1976 | +27.2 pts | Democrats |
Who Lives Here
Census & ACS county profile, 2024
Population
15,705
College (BA+)
43%
Median income
$61,620
2024 dollars
Non-white
18%
Rural
41%
Age 65+
27%
Interpolated between Census/ACS anchors; income CPI-deflated to 2024. Demographics begin in 2000 — earlier cycles have returns only.
Neighbouring counties
Henry, IA · Keokuk, IA · Van Buren, IA · Wapello, IA · Washington, IA