Iowa Senate: Party Control and History

Current seats

Republican majorityDemocrats 17, Republicans 32, vacant 1. 50 seats; 26 for a majority.

Democrats 17Republicans 32Vacant 1

Vacant: district 11. Control counts seats by party; coalitions and power-sharing agreements are not shown.

Members as of November 3, 2026 (Open States), before the winners of the November 3, 2026 elections take office.

Iowa overviewIowa House

District map

Democrat 17Republican 32Vacant 1

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2024: the candidate(s) with the most votes in each contest (MEDSL); contests with unreliable rows are not shown. Lines of the 2024 elections (US Census Bureau).

Members as of November 3, 2026 (Open States), before the winners of the November 3, 2026 elections take office.

Seats after each election, 1968-2022

Seats by election, table

Year	D	R	Other	Seats	Control
2022	16	34	0	50	Republican majority
2020	18	32	0	50	Republican majority
2018	18	32	0	50	Republican majority
2016	20	30	0	50	Republican majority
2014	26	24	0	50	Democratic majority
2012	26	24	0	50	Democratic majority
2010	26	24	0	50	Democratic majority
2008	32	18	0	50	Democratic majority
2006	30	20	0	50	Democratic majority
2004	25	25	0	50	Tied
2002	21	29	0	50	Republican majority
2000	19	31	0	50	Republican majority
1998	19	31	0	50	Republican majority
1996	21	29	0	50	Republican majority
1994	27	23	0	50	Democratic majority
1992	28	22	0	50	Democratic majority
1990	29	21	0	50	Democratic majority
1988	30	20	0	50	Democratic majority
1986	30	20	0	50	Democratic majority
1984	29	21	0	50	Democratic majority
1982	28	22	0	50	Democratic majority
1980	22	28	0	50	Republican majority
1978	22	28	0	50	Republican majority
1976	28	22	0	50	Democratic majority
1974	26	24	0	50	Democratic majority
1972	22	28	0	50	Republican majority
1970	12	38	0	50	Republican majority
1968	Not available

Carl Klarner, State Legislative Election Returns, 1967-2022: version 1.0, released June 12, 2024; a fixed historic release.

District results, 2016-2024

The candidate with the most votes in each contest.

2024: 25 contests

Incomplete in the source: counties in the file with no rows for this chamber (uncontested seats left off the ballot, or missing data).

District	Most votes	Party	Share	Note
2	JEFF TAYLOR	Republican	100.0%	one candidate
4	TIM KRAAYENBRINK	Republican	100.0%	one candidate
6	JASON SCHULTZ	Republican	81.2%
8	MARK COSTELLO	Republican	70.6%
10	DAN DAWSON	Republican	56.1%
12	AMY SINCLAIR	Republican	70.4%
14	SARAH TRONE GARRIOTT	Democrat	50.0%
16	CLAIRE CELSI	Democrat	70.1%
18	JANET PETERSEN	Democrat	100.0%	one candidate
20	MIKE PIKE	Republican	50.1%
22	MATT BLAKE	Democrat	52.5%
24	JESSE GREEN	Republican	62.5%
26	KARA WARME	Republican	59.7%
28	DENNIS GUTH	Republican	69.5%
30	DOUG CAMPBELL	Republican	61.4%
32	MIKE KLIMESH	Republican	64.7%
34	DAN ZUMBACH	Republican	66.8%
36	THOMAS TOWNSEND	Democrat	50.5%
38	DAVE SIRES	Republican	50.6%
40	ART STAED	Democrat	55.1%
42	CHARLIE MCCLINTOCK	Republican	100.0%	one candidate
44	ADRIAN DICKEY	Republican	68.5%
46	DAWN DRISCOLL	Republican	60.7%
48	MARK S LOFGREN	Republican	65.8%
50	JEFF REICHMAN	Republican	58.5%

2022: 32 contests

Incomplete in the source: rows with no district (dropped).

Incomplete in the source: counties in the file with no rows for this chamber (uncontested seats left off the ballot, or missing data).

District	Most votes	Party	Share
1	ROCKY DE WITT	Republican	55.1%
3	LYNN EVANS	Republican	99.1%
4	TIM KRAAYENBRINK	Republican	97.8%
5	DAVE ROWLEY	Republican	98.5%
6	JASON SCHULTZ	Republican	82.9%
7	KEVIN ALONS	Republican	98.0%
9	TOM SHIPLEY	Republican	76.8%
11	JULIAN B GARRETT	Republican	61.6%
13	CHERIELYNN WESTRICH	Republican	64.9%
14	SARAH TRONE GARRIOTT	Democrat	51.4%
15	TONY BISIGNANO	Democrat	95.3%
16	CLAIRE CELSI	Democrat	58.1%
17	IZAAH KNOX	Democrat	76.6%
19	KEN ROZENBOOM	Republican	68.6%
21	MIKE BOUSSELOT	Republican	50.9%
23	JACK WHITVER	Republican	58.6%
25	HERMAN C QUIRMBACH	Democrat	75.7%
27	ANNETTE SWEENEY	Republican	66.6%
29	SANDY SALMON	Republican	65.4%
31	BILL DOTZLER	Democrat	96.9%
33	CARRIE KOELKER	Republican	65.8%
35	CHRIS COURNOYER	Republican	61.0%
37	MOLLY DONAHUE	Democrat	56.0%
39	LIZ BENNETT	Democrat	64.8%
41	KERRY GRUENHAGEN	Republican	58.1%
42	CHARLIE MCCLINTOCK	Republican	58.8%
43	ZACH WAHLS	Democrat	97.5%
44	ADRIAN DICKEY	Republican	66.5%
45	JANICE WEINER	Democrat	82.0%
46	DAWN DRISCOLL	Republican	54.0%
47	SCOTT WEBSTER	Republican	56.1%
49	CINDY WINCKLER	Democrat	93.3%

2020: 25 contests

Incomplete in the source: counties in the file with no rows for this chamber (uncontested seats left off the ballot, or missing data).

District	Most votes	Party	Share
2	JEFF TAYLOR	Republican	99.3%
4	DENNIS GUTH	Republican	97.8%
6	CRAIG STEVEN WILLIAMS	Republican	69.1%
8	DAN DAWSON	Republican	52.1%
10	JAKE CHAPMAN	Republican	62.5%
12	MARK COSTELLO	Republican	69.0%
14	AMY SINCLAIR	Republican	98.2%
16	NATE BOULTON	Democrat	75.7%
18	JANET PETERSEN	Democrat	97.3%
20	BRAD ZAUN	Republican	51.1%
22	SARAH TRONE GARRIOTT	Democrat	50.1%
24	JESSE GREEN	Republican	65.7%
26	WAYLON BROWN	Republican	65.5%
28	MIKE KLIMESH	Republican	62.4%
30	ERIC GIDDENS	Democrat	51.5%
32	CRAIG JOHNSON	Republican	61.1%
34	LIZ MATHIS	Democrat	96.5%
36	JEFF EDLER	Republican	60.5%
38	DAWN DRISCOLL	Republican	63.9%
40	KEN ROZENBOOM	Republican	71.5%
42	JEFF REICHMAN	Republican	59.8%
44	TIM GOODWIN	Republican	56.7%
46	MARK S LOFGREN	Republican	59.3%
48	DAN ZUMBACH	Republican	65.1%
50	PAM JOCHUM	Democrat	58.7%

2018: 25 contests

Incomplete in the source: counties in the file with no rows for this chamber (uncontested seats left off the ballot, or missing data).

District	Most votes	Party	Share
1	ZACH WHITING	Republican	98.2%
3	JIM CARLIN	Republican	64.7%
5	TIM KRAAYENBRINK	Republican	61.9%
7	JACKIE SMITH	Democrat	51.2%
9	JASON SCHULTZ	Republican	97.8%
11	TOM SHIPLEY	Republican	67.2%
13	JULIAN GARRETT	Republican	55.9%
15	ZACH NUNN	Republican	56.9%
17	TONY BISIGNANO	Democrat	96.6%
19	JACK WHITVER	Republican	51.3%
21	CLAIRE CELSI	Democrat	66.0%
23	HERMAN C QUIRMBACH	Democrat	74.8%
25	ANNETTE SWEENEY	Republican	61.6%
27	AMANDA RAGAN	Democrat	51.0%
29	CARRIE KOELKER	Republican	53.5%
31	BILL DOTZLER	Democrat	97.6%
33	ROBERT M HOGG	Democrat	65.5%
35	TODD TAYLOR	Democrat	96.2%
37	ZACH WAHLS	Democrat	78.0%
39	KEVIN KINNEY	Democrat	54.5%
41	MARIANNETTE MILLER-MEEKS	Republican	51.7%
43	JOE BOLKCOM	Democrat	79.5%
45	JIM LYKAM	Democrat	96.1%
47	ROBY SMITH	Republican	52.8%
49	CHRIS COURNOYER	Republican	54.9%

2016: 25 contests

Incomplete in the source: counties in the file with no rows for this chamber (uncontested seats left off the ballot, or missing data).

District	Most votes	Party	Share	Note
2	Randy Feenstra	not in source	99.6%	seats not in source
4	Dennis Guth	not in source	60.6%	seats not in source
6	Mark Segebart	not in source	83.1%	seats not in source
8	Dan Dawson	not in source	54.0%	seats not in source
10	Jake Chapman	not in source	66.6%	seats not in source
12	Mark Costello	not in source	78.2%	seats not in source
14	Amy Sinclair	not in source	74.2%	seats not in source
16	Nate Boulton	not in source	59.8%	seats not in source
18	Janet Petersen	not in source	97.8%	seats not in source
20	Brad Zaun	not in source	59.4%	seats not in source
22	Charles Schneider	not in source	55.8%	seats not in source
24	Jerry Behn	not in source	63.8%	seats not in source
26	Waylon Brown	not in source	62.3%	seats not in source
28	Michael Breitbach	not in source	58.4%	seats not in source
30	Jeff Danielson	not in source	58.7%	seats not in source
32	Craig Johnson	not in source	59.9%	seats not in source
34	Liz Mathis	not in source	56.0%	seats not in source
36	Jeff Edler	not in source	52.9%	seats not in source
38	Tim Kapucian	not in source	60.0%	seats not in source
40	Ken Rozenboom	not in source	99.2%	seats not in source
42	Rich Taylor	not in source	50.2%	seats not in source
44	Thomas A. Greene	not in source	52.5%	seats not in source
46	Mark S. Lofgren	not in source	56.7%	seats not in source
48	Dan Zumbach	not in source	62.9%	seats not in source
50	Pam Jochum	not in source	63.2%	seats not in source

MEDSL precinct returns 2016-2024: a fixed historic release; the file records no release date.

Sources

Current members: Open States (CC0 1.0), commit 3a1d876 of November 3, 2026; seat totals from openstates-metadata (MIT).

Seats after each election: Carl Klarner, State Legislative Election Returns, 1967-2022, Harvard Dataverse (CC0 1.0).

District results: MEDSL precinct returns (2018-2024 CC0 1.0; 2016 MIT License).

District lines: US Census Bureau, TIGER/Line cartographic boundaries (public domain), state legislative districts 2024, 1:500,000.

Data through November 3, 2026.