DES MOINES, Iowa (AP) — Businessman Zach Lahn's win in Iowa’s Republican gubernatorial primary over President Donald Trump’s pick, Rep. Randy Feenstra, delivered a rare electoral setback for Trump in a primary season that had previously handed him back-to-back victories.

The narrow upset Tuesday revealed cracks in Trump's coalition in the deep-red state, encouraging Democrats who are hopeful they can flip control of the governor's office this year. It also marked a potential breakthrough moment for the Make America Healthy Again movement, which has clashed with the Trump administration over its embrace of pesticides and backed Lahn's message in favor of regenerative farming and against large agricultural corporations.

“I will take on the big ag cartels. I will break up their monopolies, and I will get Iowa farmers a fair deal," Lahn said in his victory speech late Tuesday.

Members of the MAHA movement, a diverse coalition of supporters of Health Secretary Robert F. Kennedy Jr. with priorities ranging from ending vaccine mandates to promoting healthy soil and organic food, cheered the win as a sign their political message was resonating with voters.

“This election is a signal that pro-pesticide does not mean pro-farmer,” said Tony Lyons, the president of the Kennedy-aligned MAHA PAC, which endorsed Lahn. “Zach Lahn made transitioning away from toxic chemicals the cornerstone of his campaign and won this election decisively with strong farmer support.”

Lahn, little known before his run, carved out a MAHA fandom

Lahn, a farmer and former conservative political director, was relatively unknown in Iowa until he launched his campaign in November. During his campaign, he championed policies that appealed to Iowa's conservative grassroots supporters, like a total ban on abortion and keeping liberal ideology out of school classrooms.

Lahn, who owns an investment company and lives on a farm in eastern Iowa that had been in his family for a century, capitalized on activists’ skepticism toward Feenstra, criticizing him for not showing up to debate his primary opponents and spending limited time on the campaign trail.

But Lahn also carved out a niche in the MAHA movement, vocally rebuking the consolidation of farmland in the hands of corporate owners and acknowledging health concerns involving farms and poor water quality.

Iowa, an agricultural stronghold, has a powerful farm lobby that has opposed mandatory rules about curbing chemicals in water. But dangerously polluted drinking water has become an increasingly urgent issue as runoff from farmland has caused surging nitrate levels that have required expensive filtration in Des Moines, the state's capital city.

Lahn said in a debate in May that water treatment system upgrades were a “Band-Aid.” He said his goal as governor would be to “decrease the nitrate load in the water in the future so we have less stress on that system.”

In recent months, activists in the MAHA movement loudly backed Lahn as they grew increasingly impatient with the Trump administration and its Environmental Protection Agency for actions they view as antithetical to making America healthier.

Earlier this year, they revolted after Trump issued an executive order aimed at boosting the production of a controversial herbicide ingredient known as glyphosate. They also organized a protest at the Supreme Court in April to protest glyphosate producer Monsanto's Trump-backed effort to shield itself from lawsuits.

Lahn has opposed liability shields for pesticide companies. He leaned into campaign points tied to those issues during his primary victory speech Tuesday night.

“Iowa has the fastest growing cancer rate in the world,” Lahn said. “We all know something is terribly wrong. But too many politicians from Washington, D.C., to Des Moines have had their heads stuck in the sand while big ag and big pharma printed money. This will not go on when I’m governor.”

Those positions helped Lahn gain endorsements from MAHA PAC and the late Charlie Kirk's conservative political organization Turning Point Action. Figures from both groups reacted to Lahn's victory by celebrating it as their own.

“MAHA has done its job proving it’s politically radioactive to stand with chemicals over children,” Turning Point USA podcaster Alex Clark said on social media. “Iowa knows pesticides are causing cancer which is exploding in their state. Tonight they opted for change.”

Kelly Ryerson, a Florida-based activist whose social media account Glyphosate Girl focuses on nontoxic food systems, said she wants midterm candidates in other states to take note.

“Decreasing pesticides and improving food quality are common ground issues that drive votes,” she said.

A setback for Trump after repeated victories

Trump had stayed quiet on Iowa's gubernatorial race until last week, when he praised Feenstra as “MAGA all the way” and said he would “fight tirelessly” for the state on issues including the economy, border security and support of law enforcement.

The power of the president's endorsement had been proven earlier in the primary season, when it helped defeat two senators — John Cornyn of Texas and Bill Cassidy of Louisiana — and Rep. Thomas Massie of Kentucky.

Some political observers had viewed Massie's loss as a stumbling block for the MAHA movement. The Republican congressman had helped lead a bipartisan effort to get liability protections for chemical companies out of a recent farm bill, in line with activists' concerns.

But Feenstra's loss marked a win for MAHA and a setback for the president. It also creates an opening Democrats are sure to try to seize.

State Auditor Rob Sand, the lone Democrat currently holding statewide office, is the party’s nominee for governor. Unopposed in the primary, Sand has been able to hone his moderate message, remind voters of his rural upbringing and amass an $18 million campaign fund.

Feenstra conceded his race to Lahn on Tuesday, signaling he was open to joining forces for the good of the party. He said he called Lahn to tell him to “carry the torch.” Lahn, looking ahead to November in his victory speech, indicated he'd campaign against Sand with a traditional conservative talking point.

“Rob Sand wants you to believe he’s a moderate,” he said. "We’ve seen this movie before.”

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Swenson reported from New York.

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