2018 Wisconsin Senate election

The 2018 Wisconsin Senate elections were held on Tuesday, November 6, 2018, at the Fall general election in Wisconsin. Seventeen of the 33 seats in the Wisconsin Senate were up for election—the odd-numbered districts. Before the election, Republicans held 18 seats and Democrats held 15 seats. Of the seats up for election, 10 were held by Republicans and seven were held by Democrats. The primary election was held on August 14, 2018.

2018 Wisconsin Senate election

← 2016 November 6, 2018 (2018-11-06) 2020 →
17 of the 33 seats in the Wisconsin State Senate 17 seats needed for a majority
Majority party Minority party   Leader Scott Fitzgerald Jennifer Shilling Party Republican Democratic Leader's seat 13th–Juneau 32nd–La Crosse Last election 9 seats, 48.62% 7 seats, 50.26% Seats before 18 15 Seats won 11 6 Seats after 19 14 Seat change 1 1 Popular vote 675,016 605,142 Percentage 52.31% 46.90%
Results of the elections:      Republican hold      Republican gain      Democratic hold      No election
President before election Roger Roth Republican Elected President Roger Roth Republican

Republicans maintained control of the Senate, flipping one Democratic-held seat to enter the 104th Wisconsin Legislature with 19 of 33 Senate seats.^[1]

Results summary

Statewide results of the 2018 Wisconsin State Senate election:^[2]

Seats		Party (majority caucus shading)		Total
		Democratic	Republican
Last election (2016)		7	9	16
Total after last election (2016)		13	20	33
Total before this election		15	18	33
Up for election		7	10	17
of which:	Incumbent retiring	1	0	1
	Vacated	0	0	0
	Unopposed	1	1	2
This election		6	11	17
Change from last election		1	1
Total after this election		14	19	33
Change in total		1	1

Party		Candi- dates	Votes		Seats
			No.	%	No.	+/–	%
	Republican Party	15	675,016	52.31%	11	1	64.71%
	Democratic Party	15	605,142	46.90%	6	1	35.29%
	Independent	1	1,776	0.14%	0		0.00%
	Write-in	2	57	0.00%	0		0.00%
	Scattering		8,346	0.65%	0		0.00%
Total		33	1,290,337	100.00%	17		100.00%

Popular vote Republican   52.31% Democratic   46.90% Other   0.79%

House seats Republican   64.71% Democratic   35.29%

Close races

Seats where the margin of victory was under 10%:

1. State Senate district 25, 2.14%
2. State Senate district 5, 2.4%
3. State Senate district 31, 5.66%
4. State Senate district 19, 6.5%
5. State Senate district 17, 8.24%
6. State Senate district 1, 9.08% (gain)

Special elections

Two special elections were held during 2018 for vacancies in the state Senate. Democrats won both special elections, for a net gain of two seats.

Dist.	Previous incumbent			This election
	Senator	Party	First elected	Candidate(s)	Result
01	Frank Lasee	Rep.	2010	▌Caleb Frostman (Dem.) 51.38% ▌André Jacque (Rep.) 48.55%	Incumbent resigned on Dec. 29, 2017. New member elected Jun. 12, 2018. Democratic gain.[3]
10	Sheila Harsdorf	Rep.	2000	▌Patty Schachtner (Dem.) 54.60% ▌Adam Jarchow (Rep.) 44.17% ▌Brian J. Corriea (Lib.) 1.22%	Incumbent resigned on Nov. 10, 2017. New member elected Jan. 16, 2018. Democratic gain.[4]

Outgoing incumbents

Retiring

• Terry Moulton (R–Chippewa Falls), representing District 23 since 2010, did not run for re-election.

Seeking other office

• Kathleen Vinehout (D–Alma), representing District 31 since 2006, ran for governor of Wisconsin, but lost in the primary.
• Leah Vukmir (R–Brookfield), representing District 5 since 2010, ran for United States Senate, but lost the general election.

Predictions

Source	Ranking	As of
Governing[5]	Tossup	October 8, 2018

Candidates and results

Results of the 2018 Wisconsin State Senate election by district:^[2]

District	Democratic		Republican		Others		Total	Result[a]
	Votes	%	Votes	%	Votes	%	Votes
District 1	39,414	45.42%	47,289	54.50%	65	0.07%	86,768	Republican gain
District 3	36,875	97.40%	-	-	985	2.60%	37,860	Democratic hold
District 5	45,591	48.75%	47,836	51.15%	102	0.11%	93,529	Republican hold
District 7	56,198	66.25%	28,459	33.55%	165	0.19%	84,822	Democratic hold
District 9	31,684	41.47%	44,680	58.47%	45	0.06%	76,409	Republican hold
District 11	-	-	59,512	95.89%	2,554	4.11%	62,066	Republican hold
District 13	34,385	40.90%	49,668	59.07%	24	0.03%	84,077	Republican hold
District 15	54,381	96.53%	-	-	1,952	3.47%	56,333	Democratic hold
District 17	31,757	45.86%	37,465	54.10%	26	0.04%	69,248	Republican hold
District 19	38,179	46.73%	43,493	53.23%	29	0.04%	81,701	Republican hold
District 21	35,111	41.91%	48,603	58.01%	69	0.08%	83,783	Republican hold
District 23	29,637	40.82%	42,958	59.17%	11	0.02%	72,606	Republican hold
District 25	39,624	51.06%	37,960	48.92%	20	0.03%	77,604	Democratic hold
District 27	64,606	66.16%	32,993	33.79%	54	0.06%	97,653	Democratic hold
District 29	27,627	35.73%	49,657	64.22%	41	0.05%	77,325	Republican hold
District 31	40,073	51.67%	35,684	46.01%	1,804	2.33%	77,561	Democratic hold
District 33	-	-	68,759	96.85%	2,233	3.15%	70,992	Republican hold
Total	605,142	46.90%	675,016	52.31%	10,179	0.79%	1,290,337

See also

• 2018 Wisconsin elections
  • 2018 Wisconsin gubernatorial election
  • 2018 Wisconsin Attorney General election
  • 2018 Wisconsin State Assembly election
  • 2018 United States Senate election in Wisconsin
  • 2018 United States House of Representatives elections in Wisconsin
• 2018 United States elections
• Wisconsin Senate
• Elections in Wisconsin
• Redistricting in Wisconsin

Notes

1. Compared to the 2014 election.