Wisconsin State Senate seat · lines in effect since 2024
Wisconsin Senate District 18
A district of about 163,000 people, 31% of adults with a bachelor's degree. It votes D+8.8 relative to the nation for president.
2024 election
Nov 5, 2024- Kristin Dassler-Alfheim (D) · won53.3%
- Anthony Wayne Phillips (R)46.7%
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 12:13 PM ET
Where it sits among all 33 seats
Every Wisconsin State Senate seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.
Democratic
Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Every election for this seat
15 races since 1968. District numbers are redrawn after each census: each group is one set of lines.
| Year | Winner | Runner-up | Won by |
|---|---|---|---|
| Lines first used in 2024 | |||
| 2024 | Kristin Dassler-Alfheim (D) | Anthony Wayne Phillips (R) | 6.6 |
| Lines first used in 2012 | |||
| 2020 | Dan Feyen (R) | Aaron M. Wojciechowski (D) | 18.3 |
| 2016 | Dan Feyen (R) | Mark L. Harris (D) | 11.8 |
| 2012 | Rick Gudex (R) | Jessica King (D) | 0.7 |
| Lines first used in 2002 | |||
| 2008 | Randy Hopper (R) | Jessica King (D) | 0.2 |
| 2004 | Carol A. Roessler (R) | — | Unopposed |
| Lines first used in 1992 | |||
| 2000 | Carol A. Roessler (R) | Kevin McGee (D) | 36.0 |
| 1996 | Carol A. Buettner (R) | Fred Frederickson (D) | 47.5 |
| 1992 | Carol A. Buettner (R) | Betty Ziewacz (D) | 24.7 |
| Lines first used in 1982 | |||
| 1988 | Carol A. Buettner (R) | Mary Gropp (D) | 37.5 |
| 1984 | Scott McCallum (R) | Peggy A. Lautenschlager (D) | 8.1 |
| Lines first used in 1972 | |||
| 1980 | Scott McCallum (R) | — | Unopposed |
| 1976 | Scott McCallum (R) | Daniel L. Klawitter (D) | 32.3 |
| 1972 | Walter G. Hollander (R) | Daryl Laatsch (D) | 29.9 |
| Lines first used in 1962 | |||
| 1968 | Walter G. Hollander (R) | Gordon E. Loehr (D) | 27.6 |
Won by: the winner's lead over the runner-up, in points of the vote. Source: 99chambers results archive (MEDSL, Klarner, state election offices)
Districts that overlap District 18
The state's districts in other chambers that share residents with this one, and the share of District 18's area in each.
Every race on these lines
Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.
| 2024 | |
|---|---|
| President | D+8.7 |
| U.S. Senate | D+10.5 |
Outlined: the race for this seat itselfBlank: no race that year
Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 8, 2026, 7:01 PM ET
Who lives here, compared
Grey bars show the spread of all 33 seats. Small marks are other seats in Wisconsin. The black marker is District 18.
Higher than 53% of seats.
Lower than 56% of seats.
Higher than 56% of seats.
Higher than 62% of seats.
Higher than 72% of seats.
Denser than 78% of seats.
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET
Seats most like this one
Nearest seats on demographics, density and lean. 1 of the 4 flipped this year.
District 3031% college gradsD+3.6Not up in 2026District 21
34% college gradsD+1.4Flipped DDistrict 31
33% college gradsD+3.2Held DDistrict 32
32% college gradsD+3.6Not up in 2026
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET