Iowa State Senate District 15
Tue, Nov 3 · Represented by Tony Bisignano Democratic · Member list as of Oct 28
One candidate on the printed ballot.
- Last election
- Tony Bisignano (Democratic) was unopposed, 2022
- Earlier results
- Zach Nunn (Republican) won by 13.9 points, 2018, older linesChaz Allen (Democratic) won by 5.1 points, 2014, older linesAll 16 elections
Past results
- Votes for listed candidates
- 12,672
- Election day
- November 8, 2022
- District map
- Same as today
Iowa Senate District 15, 1968 to 2022, 2022, every candidate Candidate Party Votes and share Share DemocraticTony BisignanoWon(incumbent) Democratic 12,07495.3% Scattered write-ins Write-in 5984.7% - Votes for listed candidates
- 29,818
- Election day
- November 6, 2018
- District map
- Older district map (2012 to 2021)
Iowa Senate District 15, 1968 to 2022, 2018, every candidate Candidate Party Votes and share Share RepublicanZach NunnWon Republican 16,98857.0% DemocraticDan Nieland Democratic 12,83043.0% - Votes for listed candidates
- 25,334
- Election day
- November 4, 2014
- District map
- Older district map (2012 to 2021)
Iowa Senate District 15, 1968 to 2022, 2014, every candidate Candidate Party Votes and share Share DemocraticChaz AllenWon Democratic 13,30752.5% RepublicanCrystal Bruntz Republican 12,00847.4% Scattered write-ins Write-in 190.1% - Votes for listed candidates
- 24,184
- Election day
- November 2, 2010
- District map
- Older district map (2002 to 2011)
Iowa Senate District 15, 1968 to 2022, 2010, every candidate Candidate Party Votes and share Share DemocraticRobert E. DvorskyWon(incumbent) Democratic 17,96474.3% LibertarianChristopher Peters Libertarian 6,09225.2% Scattered write-ins Write-in 1280.5%
1968 to 2022: State Legislative Election Returns, 1967-2022 (Carl Klarner, Harvard Dataverse), retrieved Oct 28, 2026. Compiled by Carl Klarner (Harvard Dataverse) from official returns; not an official source
Only part of this chamber is up in a given cycle. Which districts vote on which date is not on file. Last contest in this district on file: 2022.
All elections (16 for this seat)
- Votes for listed candidates
- 12,672
- Election day
- November 8, 2022
- District map
- Same as today
Iowa Senate District 15, 1968 to 2022, 2022, every candidate Candidate Party Votes and share Share DemocraticTony BisignanoWon(incumbent) Democratic 12,07495.3% Scattered write-ins Write-in 5984.7% - Votes for listed candidates
- 29,818
- Election day
- November 6, 2018
- District map
- Older district map (2012 to 2021)
Iowa Senate District 15, 1968 to 2022, 2018, every candidate Candidate Party Votes and share Share RepublicanZach NunnWon Republican 16,98857.0% DemocraticDan Nieland Democratic 12,83043.0% - Votes for listed candidates
- 25,334
- Election day
- November 4, 2014
- District map
- Older district map (2012 to 2021)
Iowa Senate District 15, 1968 to 2022, 2014, every candidate Candidate Party Votes and share Share DemocraticChaz AllenWon Democratic 13,30752.5% RepublicanCrystal Bruntz Republican 12,00847.4% Scattered write-ins Write-in 190.1% - Votes for listed candidates
- 24,184
- Election day
- November 2, 2010
- District map
- Older district map (2002 to 2011)
Iowa Senate District 15, 1968 to 2022, 2010, every candidate Candidate Party Votes and share Share DemocraticRobert E. DvorskyWon(incumbent) Democratic 17,96474.3% LibertarianChristopher Peters Libertarian 6,09225.2% Scattered write-ins Write-in 1280.5% - Votes for listed candidates
- 19,027
- Election day
- November 7, 2006
- District map
- Older district map (2002 to 2011)
Iowa Senate District 15, 1968 to 2022, 2006, every candidate Candidate Party Votes and share Share DemocraticRobert E. DvorskyWon(incumbent) Democratic 19,027100.0% - Votes for listed candidates
- 21,506
- Election day
- November 5, 2002
- District map
- Older district map (2002 to 2011)
Iowa Senate District 15, 1968 to 2022, 2002, every candidate Candidate Party Votes and share Share DemocraticRobert E. DvorskyWon(incumbent) Democratic 12,82759.6% RepublicanJack Young Republican 8,67940.4% - Votes for listed candidates
- 20,777
- Election day
- November 3, 1998
- District map
- Older district map (1992 to 2001)
Iowa Senate District 15, 1968 to 2022, 1998, every candidate Candidate Party Votes and share Share DemocraticBetty SoukupWon Democratic 10,45350.3% RepublicanAllen Borlaug(incumbent) Republican 10,32449.7% - Votes for listed candidates
- 21,217
- Election day
- November 8, 1994
- District map
- Older district map (1992 to 2001)
Iowa Senate District 15, 1968 to 2022, 1994, every candidate Candidate Party Votes and share Share RepublicanAllen BorlaugWon(incumbent) Republican 12,17757.4% DemocraticJames A. Erb Democratic 9,04042.6% - Votes for listed candidates
- 19,278
- Election day
- November 6, 1990
- District map
- Older district map (1982 to 1991)
Iowa Senate District 15, 1968 to 2022, 1990, every candidate Candidate Party Votes and share Share RepublicanAllen BorlaugWon Republican 9,99851.9% DemocraticKenneth D. Scott(incumbent) Democratic 9,28048.1% - Votes for listed candidates
- 19,208
- Election day
- November 4, 1986
- District map
- Older district map (1982 to 1991)
Iowa Senate District 15, 1968 to 2022, 1986, every candidate Candidate Party Votes and share Share DemocraticKenneth D. ScottWon Democratic 9,72650.6% RepublicanPaul Bunge Republican 9,48149.4% Scattered write-ins Write-in 10.0% - Votes for listed candidates
- 21,435
- Election day
- November 2, 1982
- District map
- Older district map (1982 to 1991)
Iowa Senate District 15, 1968 to 2022, 1982, every candidate Candidate Party Votes and share Share RepublicanArthur L. GratiasWon(incumbent) Republican 12,32757.5% DemocraticGary Bernau Democratic 9,10342.5% Scattered write-ins Write-in 50.0% - Votes for listed candidates
- 16,201
- Election day
- November 7, 1978
- District map
- Older district map (1972 to 1981)
Iowa Senate District 15, 1968 to 2022, 1978, every candidate Candidate Party Votes and share Share DemocraticBob RushWon Democratic 8,84754.6% RepublicanLloyd E. Humphreys Republican 7,35445.4% - Votes for listed candidates
- 17,449
- Election day
- November 4, 1974
- District map
- Older district map (1972 to 1981)
Iowa Senate District 15, 1968 to 2022, 1974, every candidate Candidate Party Votes and share Share DemocraticSteve SovernWon Democratic 9,93156.9% RepublicanRalph W. Potter(incumbent) Republican 7,51843.1% - Votes for listed candidates
- 22,615
- Election day
- November 7, 1972
- District map
- Older district map (1972 to 1981)
Iowa Senate District 15, 1968 to 2022, 1972, every candidate Candidate Party Votes and share Share RepublicanRalph W. PotterWon(incumbent) Republican 13,30758.8% DemocraticBernard Beuter Democratic 9,30841.2% - Votes for listed candidates
- 23,828
- Election day
- November 5, 1968
- District map
- Older district map (1966 to 1969)
Iowa Senate District 15, 1968 to 2022, 1968, every candidate Candidate Party Votes and share Share RepublicanHarold A. ThordsenWon Republican 11,93950.1% DemocraticJoseph W. Cassidy(incumbent) Democratic 11,88949.9% - Votes for listed candidates
- 4,003
- Election day
- November 5, 1968
- Type
- Special election
- District map
- Older district map (1966 to 1969)
Iowa Senate District 15, 1968 to 2022, 1968, every candidate Candidate Party Votes and share Share RepublicanEdward E. NicholsonWon Republican 2,62365.5% DemocraticKarl H. Hellman Democratic 1,37134.3% Scattered write-ins Write-in 90.2%
More about this race
Uncontested
One candidate on the printed ballot.
Source: sos.iowa.gov (PDF), dated Aug 19
District map
- Democratic
- Republican
- Independent
- Nonpartisan
- More than one party
- No member listed
Map settings
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Cite this page
Election Wrld. (2026). Iowa State Senate District 15, election results 1968 to 2022. https://www.electionwrld.com/ia/senate/15. Retrieved October 31, 2026.
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<p style="font-size:13px">Data: <a href="https://www.electionwrld.com">Election Wrld</a>, CC BY 4.0</p>Sources
Sources: Census TIGERweb Legislative MapServer (120th CDs layer 0, 119th CDs layer 4, 2026 SLD upper layer 1 and lower layer 2) (US Census Bureau, public domain), retrieved Oct 28, 2026; Open Civic Data division identifiers (census_autogenerated us_sldl/us_sldu and openstates state files); also (sld-recent.json): Open Civic Data division identifiers (country-us) (CC0 (repository); also (sld-recent.json): CC0 1.0), retrieved Oct 28, 2026; Open States people (current) CSVs (CC0-1.0 (Open States people data)), retrieved Oct 28, 2026, compiled by Open States volunteers and staff (rosters from state legislature sites) from official returns, not an official source; State Legislative Election Returns, 1967-2022 (Carl Klarner, Harvard Dataverse) (CC0 1.0), retrieved Oct 28, 2026, compiled by Carl Klarner (Harvard Dataverse) from official returns, not an official source.
DataState data (JSON)Sources: State Legislative Election Returns, 1967-2022 (Carl Klarner, Harvard Dataverse), DIME (ODC-BY)Data as of Oct 28, 2026