On Jan. 28, Mike Zimmer (D) defeated Katie Whittington (R) in the special election for Iowa Senate District 35, 51.7% to 48.1%.

The seat became vacant in November 2024 after Gov. Kim Reynolds (R) appointed Sen. Chris Cournoyer (R) to serve as lieutenant governor. The last time that the seat was up for election in 2022, Cournoyer defeated Jed Ganzer (D) 61% to 39%. The seat was previously held by Rita Hart (D).

In the 2024 presidential and congressional elections, President Donald Trump (R) won the district by 21 percentage points, and Rep. Mariannette Miller-Meeks (R) won by nine percentage points.

According to the Secretary of State’s office, Republicans have an edge regarding party registration. At the time of the election, 12,246 registered Democrats lived in the district, 15,598 Republicans, and 372 minor party voters. Additionally, 19,390 voters were registered as having no party affiliation.

Leading up to the special election, Iowa Starting Line’s Zachary Oren Smith wrote that the “campaigns [had] less than a month to organize. And special elections tend to have low turnout since they occur outside the normal November election period. The condensed, off-calendar timing makes the special election unpredictable.”

Despite Democrats gaining a seat, Republicans will still have a two-thirds majority in both legislative chambers. 

In 2024, all 100 seats in the Iowa House of Representatives and 25 seats in the Iowa Senate were up for election. As a result of the 2024 general elections, Republicans increased their majority in both chambers. The Republican majority in the House increased from 64-36 to 67-33, and the Republican majority in the Senate increased from 33-16 with one vacancy to 34-16 with one vacancy. 

That makes the Iowa General Assembly one of 28 state legislatures where one party had a supermajority in both chambers. According to the Des Moines Register’s Stephen Gruber-Miller, this was the largest Republican majority in both chambers since 1970.

Iowa is also one of 23 states with a Republican trifecta. Republicans gained a trifecta in the state after gaining control of the Senate following the 2016 general elections.

This special election is one of 27 legislative special elections that have been called so far for 2025.