County record · fips 17111 · Illinois
McHenryIL
Republican ×4 since 2012all 40 elections, 1868–2024
The Long Record
40 elections against the Illinois and national vote
2024 result
R+5.4
won by Republicans
Record since first cycle
1–39
Dem–Rep two-party wins
Voted with the winner
24/40
60% of its elections
Closest election
2020
R+2.6
this countyIllinoisnational (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 |
|---|---|---|
| 1876 | +68.8 pts | Democrats |
| 1872 | -57.6 pts | Republicans |
| 1928 | +41.7 pts | Democrats |
| 1912 | +37.0 pts | Democrats |
| 1916 | -36.0 pts | Republicans |
Who Lives Here
Census & ACS county profile, 2024
Population
312,591
College (BA+)
35%
Median income
$104,802
2024 dollars
Non-white
24%
Rural
14%
Age 65+
16%
Interpolated between Census/ACS anchors; income CPI-deflated to 2024. Demographics begin in 2000 — earlier cycles have returns only.
Neighbouring counties
Boone, IL · Cook, IL · DeKalb, IL · Kane, IL · Lake, IL · Kenosha, WI · Walworth, WI