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.

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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.