This briefing reflects information available as of September 5, 2026. IA-03 is a live, competitive race, and candidates, polling, and endorsements may change before the November 3 election.
Why This Race Matters
Iowa’s 3rd Congressional District, anchored in the Des Moines metro, has flipped between the parties twice in the past three cycles and decided its last two elections by a few points or less. Republican Rep. Zach Nunn is seeking a third term against Democratic state Sen. Sarah Trone Garriott in a race both national parties consider genuinely competitive.
Unlike several other 2026 battlegrounds, this district was not redrawn. Its lines have stayed the same since 2022, so this race is a test of whether Nunn’s brand of bipartisan positioning can hold up in a midterm environment that has historically punished the president’s party.
The Race
The Cook Partisan Voting Index rates IA-03 as R+2. Nunn first won the seat in 2022, defeating then-Rep. Cindy Axne by less than one point, 50.3 percent to 49.6 percent. He won reelection in 2024 by about 4 points, running roughly even with Donald Trump’s margin in the district that year.
IA-03 covers the Des Moines metro area, including Polk, Dallas, and Warren counties, along with several rural counties to the south. It is home to the state’s largest concentration of insurance and financial-services jobs as well as a growing suburban population in fast-growing communities like West Des Moines, where Trone Garriott lives.
Both candidates ran unopposed in their June 2 primaries after Trone Garriott’s rivals, including former House Minority Leader Jennifer Konfrst, withdrew and endorsed her. Bleeding Heartland reported that as of March 31, Nunn’s campaign held more cash on hand, about $3.04 million to Trone Garriott’s $2.19 million, though her fundraising from individual donors reportedly outpaced his.
Cook Political Report and Sabato’s Crystal Ball both rate the race a toss-up, while Inside Elections rates it Lean Republican, a split similar to what forecasters show in several other 2026 House races. The Rural Margin reported that American Action Network, a Republican-aligned outside group, has put more than $1 million behind Nunn as part of a $22 million summer ad campaign across Iowa’s competitive districts.
The Democratic Congressional Campaign Committee has listed IA-03 on its Red to Blue program, and House Republican leadership, including Majority Leader Steve Scalise, has campaigned in the district on Nunn’s behalf. Both parties are treating this as one of a small number of races that could shift control of the House.
The Candidates
Zach Nunn (R) is a Colonel in the Air Force Reserve who deployed multiple times after 9/11 and later worked in national counterintelligence and White House cybersecurity policy roles before entering politics. He served in the Iowa House and Senate before winning this seat in 2022. In Congress he sits on the Financial Services Committee and the Select Committee on Strategic Competition with the Chinese Communist Party, and has sponsored provisions in the 2026 Farm Bill and a rural housing reform measure.
Nunn was the only member of Iowa’s all-Republican House delegation to break ranks on health care twice in 2026, Bleeding Heartland reported, joining Democrats in January on a three-year extension of enhanced Affordable Care Act subsidies and later co-sponsoring a narrower two-year version with income caps and anti-fraud provisions. He has said he does not support the ACA itself but argues Congress should not “leave 100,000 Iowans behind because of bad prior policies.”
Sarah Trone Garriott (D) is a Lutheran pastor and state senator who has twice flipped Republican-held Iowa Senate seats, first in 2020 and again in 2022 when she moved districts after redistricting to defeat sitting Senate President Jake Chapman. She was reelected in 2024 by just 29 votes after a recount. She holds a bachelor’s degree from Swarthmore and a Master of Divinity, and has centered her campaign on lowering health care and living costs.
In the Iowa Senate, Trone Garriott introduced legislation to expand school-based mental health services through Medicaid, allowing students to receive care before a formal diagnosis, and renewed calls for more school mental health funding after the 2024 Perry High School shooting in her broader legislative area. She has criticized the 2025 reconciliation law’s tax cuts on tips and overtime, arguing its accompanying Medicaid cuts outweigh the benefit, and has said she would support repealing those provisions.
Top Issues
Health care. This is the race’s central issue. Nunn points to his crossover votes on ACA subsidies as evidence of bipartisan problem-solving, and The Gazette noted he was the only Iowa Republican to back the extension; Trone Garriott and national Democrats argue his broader record, including support for Medicaid cuts in the 2025 reconciliation law, undercuts that framing.
The economy and jobs. Trone Garriott’s campaign has highlighted Iowa’s manufacturing job losses and slow 2025 economic growth. Nunn’s campaign counters with the tax cuts on tips and overtime from the 2025 reconciliation law, which outside groups are advertising heavily on his behalf.
Transgender athletes in school sports. Nunn has run an ad accusing Trone Garriott of voting against protections for girls’ sports, and argues her positions are out of step with most Iowans on that issue and on school curriculum materials. Trone Garriott’s campaign has pushed back on how her record is being characterized.
Congressional stock trading. Nunn has co-sponsored legislation to bar members of Congress from trading individual stocks, though the bills have not received a floor vote. Internal polling reported by Bleeding Heartland suggests Republicans may test this as a general-election message for Nunn.
Evidence Check
Nunn’s claim to bipartisan credentials has some real backing: GovTrack’s 2024 analysis found he attracted bipartisan cosponsors on the third-most bills of any House member that year. That is a genuine, if narrow, metric, and it does not by itself settle broader disputes over his voting record on issues like Medicaid.
The claim that Trone Garriott’s positions are “out of step with 80% of Iowans” on gender-affirming care and school materials comes from Nunn’s own campaign messaging. We could not locate the underlying poll or independently verify that specific figure at the time of writing, so we are attributing it to Nunn rather than treating it as an established fact.
The claim of roughly 15,300 Iowa job losses in 2025 traces back to Iowa Workforce Development data as reported by Bleeding Heartland, a Democratic-leaning Iowa political site. The underlying figure comes from a state agency, but we have not independently confirmed it against the original report, so we are flagging the secondhand sourcing rather than treating it as independently verified by this outlet.
Nunn’s position on the ACA is more of a bridge than a contradiction, though both sides describe it differently. He has said plainly he does not support the ACA as a program while also voting twice to extend its subsidies through 2026 and beyond, a shift Iowa Starting Line noted came weeks after he criticized the same subsidies. The DCCC calls this an election-year conversion; Nunn calls it a short-term fix paired with longer-term reform. Both characterizations describe the same set of votes, and we are not in a position to adjudicate which motive is accurate.
Supporter Voices
Former Democratic candidate Jennifer Konfrst, a sitting Iowa House member who withdrew from this race to endorse Trone Garriott, said in a statement that Trone Garriott has “stayed focused on what matters” for Iowa families. That is a genuine district-adjacent political voice, though it comes from a former rival rather than an ordinary voter.
Nunn’s most visible public backing in available reporting comes from national party leadership, including Majority Leader Steve Scalise’s campaign appearance in the district, rather than from named local supporters. We were not able to locate an on-record quote from an ordinary IA-03 voter for either candidate, a gap worth being direct about rather than filling with a leadership press release.
How This Race Is Being Framed
Republicans are framing Trone Garriott as too liberal for the district; Iowa Capital Dispatch reported that Scalise’s visit to Iowa included comments tying her to left-wing politics, though we found no specific voting record or policy proposal cited to substantiate that particular label, and we are treating it as characterization rather than a checkable claim.
Democrats are framing Nunn as a Trump loyalist whose recent bipartisan votes on health care are timed to his reelection. National figures, including Michigan Sen. Elissa Slotkin, have campaigned in Iowa for Trone Garriott, and the DCCC’s Katie Smith argued Nunn is “waking up to the reality” of a competitive race, a characterization Nunn’s campaign rejects in favor of describing his votes as consistent with past bipartisan work.
The split between Cook and Sabato’s toss-up rating and Inside Elections’ Lean Republican call reflects genuine disagreement about how much a national Democratic environment would matter in a district Nunn has now won twice, each time by a relatively narrow but not razor-thin margin.
Related Links
- Bleeding Heartland: Nunn’s political vulnerabilities
- Iowa Capital Dispatch: Scalise campaigns for Nunn
- The Rural Margin: outside money in IA-03
- Bleeding Heartland: Nunn’s ACA crossover vote
- Iowa Starting Line: Nunn’s ACA shift
- Konfrst suspends her campaign, endorses Trone Garriott
- The Gazette: Iowa delegation splits on ACA
Discussion Questions
- Have rising health care costs affected your own family’s decisions in the past year?
- Does a lawmaker’s willingness to break with their own party on one issue change how you see their overall record?
- Why do you think forecasters disagree about how much a national political mood matters in a district like this one?
- What would it take for you to trust a specific statistic, like “80% of Iowans,” cited in a campaign ad?
- Should outside spending groups be required to disclose more about how they test campaign messages before an election?
- Do you find Nunn’s or Trone Garriott’s explanation of the ACA subsidy votes more convincing?
- How should voters weigh a candidate’s past electoral margins when deciding how competitive a race really is?
- What responsibility do national party leaders have when the labels they use about a candidate go unverified?
- Why might Iowa’s manufacturing job numbers matter more in this race than in past cycles?
- Imagine you are a swing voter in the Des Moines suburbs. What single vote or statement would most change your mind?
