Iowa established primary elections as the method for nominating candidates in 1907, and the first official statewide primary was held in 1908. All primaries have been in early June, except 1966 and 1968 (September) and 1972 (August), when redistricting forced delays.


Johnson County voters set new records for overall turnout, Democratic turnout, and early voting in the 2020 primary. 29,142 voters, including 24,652 Democrats, participated. The previous primary turnout record was set in the 2018 primary with 18,675 voters.

The 2020 primary set a record for the highest share of votes cast early in any Johnson County election. 22,370 voters (76.76% of total turnout) voted before Election Day. While our office had limited in-person early voting and no satellite sites, we mailed more ballots than we had in any previous election, including presidential elections.

With 4,490 Republican voters, 2020 saw the third highest Republican primary turnout in county history. The Republican primary turnout record was set in 1994. 6,192 people voted in that primary, which featured a race for Governor between incumbent Terry Branstad and Congressman Fred Grandy.

The Libertarian Party had its first primary in 2018 and set a new record for third parties with 82 voters. The previous record was 48 voters in the 2002 Green Party primary.

Low Turnout

The low turnout records are from years with no contested races. The 2004 Republican primary turnout of 630 voters was the lowest in at least 40 years. The 2002 Democratic primary total of 1,062 voters was the lowest since the June 1920 primary - held two months before the passage of the 19th Amendment giving women the right to vote.

Primary Turnout and Contests, 1984-present

Primary Date Total Turnout Democratic Republican
Turnout Contests Turnout Contests
June 5, 1984 5,903 5,257 Supervisor, House 45, Clerk of Court 644 House 54
June 3, 1986 * 8,186 6,300 Gov.,Lt. Gov., US Sen., US Rep., Ag. Sec., House 54, Supervisor 1,476 Lt. Gov., Ag. Sec., Senate 27
June 7, 1988 7,342 6,159 US Rep., Sheriff, Supervisor 1,183 US Rep.
June 5, 1990 9,931 8,995 Governor, State Auditor, Supervisor 936 Attorney General
June 2, 1992 7,748 6,731 US Senate, Supervisor 1,017 House 49
June 7, 1994 13,418 7,226 Governor, US Rep. Sec. of State, Supervisor, House 49 6,192
(Rep record)
Governor, House 46
June 4, 1996 9,858 7,661 US Rep, Auditor, Supervisor, House 45 2,197 US Senate
June 2, 1998 * 10,296 8,309 Governor, US Rep, Sec. of State, Recorder, Treasurer, Supervisor 1,966 Governor, Sec. of Ag.
June 6, 2000 7,503 6,655 US Rep, Supervisor, House 45 848 none
June 4, 2002 * 4,496 1,062 none 3,386 Governor, US Senate
June 8, 2004 9,305 8,675 Supervisor, Sheriff 630 none
June 6, 2006 11,906 11,066 Governor, Sec. of Ag., Co. Atty., Supervisor 840 Sec. of State, Sec. of Ag.
June 3, 2008 5,130 3,652 Auditor, Supervisor 1,478 US Senate, US Representative
June 8, 2010 8,985 4,138 US Senate, House 30 4,847 Governor, US Rep, Sec. of State, State Treasurer, Senate 45, House 89
June 5, 2012 6,902 5,329 US Rep, Auditor, House 73 1,573 US Rep
June 3, 2014 10,885 7,582 Co. Atty., Supervisor, Senate 39, House 73 3,303 Governor, US Senate, US Rep, Senate 39
June 7, 2016 8,896 8,189 US Senate, House 77, Supervisor 707 House 77
June 5, 2018 * 18,675 17,144 Governor, Sec. of State, Senate 37, Supervisor 1,438 Sec. of Ag.
June 2, 2020


(Dem record)
US Senate, House 85, Supervisor, Sheriff 4,490 US Rep
June 7, 2022


15,321 US Senate, Sec. of State, Senate 45, House 89 and 90, Supervisor 3,893 US Senate, State Auditor, House 91 and 92

* The 1986 total includes 410 no party voters who voted in Iowa City and Coralville bond issue elections held with the primary. The no party voters received a ballot that included only the bond issue and no nominating contests. State law has since changed, and ballot issues may no longer be combined with primary elections.

The 1998 total includes 21 voters in the Reform Party primary (contested race: governor).

The 2002 total includes 48 voters in the Green Party primary (no contested races).

The 2018 total includes 82 voters in the Libertarian Party primary (contested race: governor).

Highest Vote Totals for Candidates

The record for highest vote total in a contested race was set in 2020. Democratic sheriff nominee Brad Kunkel won 19,561 votes. The old record was in 2018 by Supervisor Janelle Rettig with 10,826 votes in the Democratic primary.

The candidates receiving the highest vote totals in primaries were all uncontested:

  • Democratic: 22,254 for congressional candidate Rita Hart in 2020.
  • Republican: Congressman Jim Leach won 5,044 votes in 1994.
  • Third Party: Jay Robinson won 43 votes in the 2002 Green Party primary for governor.

Uncontested Primaries

Unlike a city primary, a partisan primary election must be held even if no races are contested. The 2000 and 2004 Republican primaries had no contested races. Most Johnson County Republicans also had a ballot with no contests in 1984, 1992 and 2016 (the only contests those years were in one legislative district).

In 2002, for the first, and so far the only, time in history, there were no contested races on the Johnson County Democratic primary ballot. Every previous Democratic primary in Johnson County, from 1908 through 2000, had at least one contested race.

The Green Party had no contested races in its one primary in 2002.

Most Candidates

The largest field of primary candidates ever was in the 1976 primary election. 15 candidates were simultaneously running in three separate contests for three Board of Supervisors seats:

  • Ten Democratic candidates ran for two full-term seats.
  • Two Republicans ran for the two full-term seats.
  • Three Democrats ran for an unexpired term.

13 of these candidates appeared on the Democratic ballot.

Close Elections

The closest Johnson County primary in recent years was the 1998 contest for the Democratic nomination for county treasurer. Tom Kriz defeated Pam Lenz Nielsen by 28 votes.

Write-In Candidates

To win a nomination as a write-in, a candidate must win 35% of the vote. Two candidates earned enough write-in votes to win Republican nominations in 2020: auditor Travis Weipert and sheriff candidate Brad Kunkel. Both these candidates were on the Democratic primary ballot. Candidates may only accept the nomination of one party; both Weipert and Kunkel declined the Republican nomination and accepted the Democratic nomination instead.

The last candidate in Johnson County actually nominated as a write-in was Bob Vevera, in the 1988 Republican primary for sheriff.

Inconclusive Primaries and Special Nominating Conventions

If no candidate wins 35% in a primary, the primary is inconclusive and the political party must hold a nominating convention. This happened in the Republican race for Secretary of Agriculture in 2018. Appointed incumbent Mike Naig finished in first place in a five way contest, but was short of the required 35%. Naig was later nominated at the Republican state convention and elected in November.

The last inconclusive primary in Johnson County was the 1964 Democratic primary for sheriff. Harold Smith finished first in a six candidate contest, but only won 27% of the vote. Maynard Schneider finished second with 24%. Schneider was nominated at the convention and elected in November.

Parties may also nominate candidates by convention to fill ballot vacancies. Johnson County Republicans nominated two area legislative candidates by convention in 2022. The Libertarian and Republican parties nominated several statewide candidates at their 2018 state conventions.

Lieutenant Governor

Through the 1986 election cycle, candidates for lieutenant governor were nominated in the primary and elected, independent of the election for governor, in the general election. It was thus possible for the governor and lieutenant governor to be from different parties. This happened in 1986, when Republican Terry Branstad was re-elected governor and Democrat JoAnn Zimmerman was elected lieutenant governor.

In 1988, Iowa voters approved a constitutional amendment requiring the governor and lieutenant governor to run as a team. The amendment took effect beginning with the 1990 elections. Candidates for lieutenant governor no longer appear on the primary ballot, and are instead nominated by state party conventions after the primary. So far, all such conventions have confirmed the gubernatorial candidate's chosen running mate.

Candidates for governor are not required to name running mates before the primary, and even if they do, the name of the running mate does not appear on the ballot.

In 1990, incumbent Lt. Governor Zimmerman initially filed to run for governor, but withdrew from the race after the withdrawal deadline, endorsed House Speaker Don Avenson, and agreed to be his running mate. Avenson then won the primary (in which Zimmerman's name still appeared on the ballot). Thus Zimmerman ran for re-election, on a ticket with Avenson, against incumbent Governor Branstad's ticket.

Prior to the 2006 primary, three candidates - Republican nominee Jim Nussle, Democratic nominee Chet Culver, and unsuccessful Democratic candidate Mike Blouin - each named running mates. It was the first time any non-incumbent candidates for governor had named running mates before the primary since the Avenson-Zimmerman ticket of 1990. Two other Democratic candidates, Ed Fallon and Sal Mohamed, did not name running mates. No candidates for governor have named running mates before the primary since 2006.