Iowa’s 3rd Congressional District is a Des Moines-anchored U.S. House seat covering central and southern Iowa, currently represented by Republican Zach Nunn and rated one of the most competitive races in the country for 2026. With a Cook Partisan Voting Index of R+2, it has produced razor-thin margins in back-to-back cycles and is again a toss-up heading into the midterms.
Where the District Is
The district stretches across more than 50 counties. Its population center is the Des Moines metro, including Des Moines itself along with Ankeny, West Des Moines, Urbandale, Waukee, and Johnston. Beyond the suburbs it takes in Ames, home of Iowa State University, along with Waterloo, Cedar Falls, Marshalltown, Fort Dodge, and Ottumwa, and dozens of smaller rural communities running south to the Missouri border and west toward Council Bluffs.
About 837,900 people live in the district. It is roughly 77 percent White, 9 percent Hispanic, 6 percent Black, and 4 percent Asian. Median household income is around $80,284, and 38 percent of residents 25 and older hold a bachelor’s degree or higher.
Who Represents the District
Zach Nunn, a Republican, is serving his second term. Before Congress he served in both the Iowa House and Iowa Senate. He is a Colonel in the Air Force Reserve, flew reconnaissance missions as an airborne intelligence officer, completed three post-9/11 deployments to the Middle East, and served as Director of Cybersecurity on the National Security Council at the White House.
In the 119th Congress, Nunn sits on the House Financial Services Committee, the House Agriculture Committee, and the House Select Committee on the Chinese Communist Party. His recent legislative work has focused on national security, financial protection for seniors, agriculture, and China policy, including the Stop Chinese Fentanyl Act, which passed the House, and the bipartisan TRAPS Act aimed at payment scams targeting older Americans.
The 2026 Race
Nunn is running for a third term with no Republican primary challenger. Vice President JD Vance traveled to Des Moines in May 2026 to rally support for his campaign, telling the crowd it is “not a normal political environment.” The Cook Political Report and Sabato’s Crystal Ball both rate the contest as highly competitive, and the Democratic Congressional Campaign Committee lists it as one of 45 “Districts in Play” as Democrats look for the three flips they need to take the House.
The Democratic nominee is State Senator Sarah Trone Garriott, a 46-year-old Lutheran pastor from West Des Moines who launched her campaign in May 2025. First elected to the Iowa Legislature in 2020, she won a redrawn Trump-leaning district in 2024 after a recount and describes herself as the only Iowa Democrat to have flipped two seats from red to blue. Her platform centers on lowering costs for child care, health care, and housing, along with “restoring the rights and freedoms lost in recent years.” She became the party’s de facto nominee after Iowa House Minority Leader Jennifer Konfrst suspended her campaign in January 2026 and endorsed her, citing a fundraising gap.
Libertarian Marco Battaglia also filed to run, though his ballot access was challenged before the State Objection Panel in June 2026.
Fundraising
Both major-party candidates have raised substantial sums. Through mid-May 2026, Nunn’s campaign committee reported approximately $4.1 million in total receipts and about $3.2 million in cash on hand. Trone Garriott’s committee reported roughly $3.9 million in receipts and about $2.7 million cash on hand. Neither carried debt. Reports from early 2026 indicated Iowa Democrats in competitive congressional races had begun outraising Republican incumbents in quarterly FEC filings.
Issues in Play
Costs are driving much of the debate. Rising fuel and fertilizer prices, tied in part to the U.S.-Iran conflict that began in early 2026, are pressuring Iowa farmers and consumers. Gas reached a national average of $4.54 per gallon by May 2026, and fertilizer costs climbed roughly $300 per ton between August 2025 and April 2026. The Trump administration’s tariffs on Chinese goods have become a flashpoint: the administration announced $12 billion in one-time bailout payments to affected farmers in December 2025, and Democrats have attacked the tariffs as raising costs for Iowa families.
Trone Garriott has criticized Nunn over the closure of health care clinics in Ottumwa and South Des Moines and for voting in line with an administration she says is making “everything more expensive.” Nunn has gone on offense over cultural issues, criticizing Trone Garriott’s past comments about legislative diversity and her affiliation with a pastor who officiated a wedding involving self-identified satanists.
Recent Election Results
The district has been decided by narrow margins in back-to-back cycles.
2022
Then-state senator Nunn unseated one-term Democratic incumbent Cindy Axne by 2,145 votes out of more than 310,000 cast, taking 156,262 to Axne’s 154,117. The Cook Political Report had rated the race Lean Republican. Inflation, abortion access after the Supreme Court overturned Roe v. Wade, border security, and U.S. relations with China dominated the contest.
2024
Nunn defeated Democrat Lanon Baccam, a Tai Dam refugee who grew up in Mount Pleasant, served in the Iowa Army National Guard with a deployment to Afghanistan, and worked at the U.S. Department of Agriculture under former Governor Tom Vilsack. Baccam centered his campaign on reproductive rights and built a sizable lead in Polk County, the district’s Democratic stronghold, but Nunn offset those margins in fast-growing Dallas County and rural areas. Nunn won roughly 52 percent to 48 percent, a margin of about 3.8 points and roughly 15,800 votes. Cook had rated the race a toss-up. Baccam faced $5.1 million in outside opposition spending, and about 70 percent of his donations came from out of state.
How the Map Was Drawn
Iowa redrew its congressional map in 2021 through a process unusual among U.S. states. The nonpartisan Legislative Services Agency drafts proposed maps, and the legislature votes them up or down. The Republican-controlled legislature rejected the LSA’s first proposal, which would have created a more Democratic-leaning seat in eastern Iowa, and approved the agency’s second plan. Governor Kim Reynolds signed the map on November 4, 2021. The enacted map split zero counties, reflecting Iowa’s standards prioritizing compact districts and intact county boundaries.
What 2030 Could Change
Population estimates released in late 2024 suggest Iowa is on track to keep all four of its congressional seats after the 2030 census. Polk County’s continued growth is increasing the Democratic share of voters in the 3rd District, and Dallas County, the fastest-growing county in the state, is expected to stay within the district’s boundaries under Iowa’s nonpartisan standards. If both remain, the redrawn seat would likely contain fewer small rural counties where Republicans typically run up large margins. Had Iowa dropped to three districts, Republicans would have been favored to win all of them.