As the debate season kicked off in Iowa’s heated gubernatorial race, one question seemed to animate and, in some ways, unify the candidates.

“What are the immediate and specific steps that you would take to combat Iowa’s cancer crisis?” the moderator asked the Democrat Rob Sand and Republican Zach Lahn, who both said it was a foundational issue for their campaigns — before each accusing the other of not doing enough.

Two weeks later, Iowa’s elevated cancer rates and their potential links to farm pollution came up again, at a debate in the competitive race for Senate.

The subject would have been unimaginable just a few years ago in Iowa, the country’s biggest corn and hog-producing state.

But the role of “Big Ag” has become a political lightning rod amid what is being described as a public health crisis. Iowa suffers from the second-highest cancer rate in the US and is one of only three states where the rate is rising.

For the first time, tackling the environmental causes of cancer has been included in Iowa campaign platforms for both parties. Republicans and Democrats up and down the ticket have staked out positions vowing to take on the issue.

In the governor’s race, Lahn, a farmer-turned-candidate backed by the “Make America Healthy Again” wing of the GOP, and Democrat Sand, a moderate lawyer, have made campaign trail promises to clean up water and regulate chemicals.

In the tight Senate race, Republican Congresswoman Ashley Hinson and Democratic State Representative Josh Turek have wrestled with the question too, both calling this month for more funding to ensure safe drinking water.

This year, nearly $30 million has been spent airing more than 100 campaign ads in Iowa that mention cancer, according to AdImpact data. In the last midterms in 2022, there was just one, backed by a little under $200,000.

“Nine months ago, there was no candidate talking about this except me, and now literally every candidate is featuring it in their campaign,” said Chris Jones, a long-time water quality advocate and now Democratic candidate for state agriculture secretary.

Yet both parties face the awkward challenge of balancing criticism of “Big Ag” practices with Iowa’s economic reliance on the sector. On the left, Jones argues Democrats have not been bold enough to take on Big Ag, ceding ground to Republicans energized by MAHA. He has gone further than any of the other candidates on the ballot in calling for more regulation and a move away from dependence on corn and soybean production.

“You’ve got an issue here that should be a natural issue for Democrats: Clean environment,” he told CNN. But the party was “too chicken to take this issue up,” he said.

But divisions within the Republican Party dent its credibility, argues Sara Schreiber of the League of Conservation Voters, with some MAHA voters disillusioned by Trump’s unkept promises for their movement.

“They want elected officials to be responsive” to their cause – health and the environment chief among them – “and they’re not just going to be partisan,” she said.

Iowa’s Health Department attributes much of its soaring cancer rates to several lifestyle factors: Obesity, alcohol and smoking chief among them. But it acknowledged that environmental exposures could play a role, inflaming Iowans who see cancer in their community.

Environmental advocates and some farmers highlight the concentration of nitrate from thousands of tons of livestock manure that leaks into the state’s waters as a key culprit.

A state cancer report showing Iowa’s sobering rates –– the fastest-rising in the country — “was really the game changer,” for average Iowans, said Zach Smith, a farmer and founding member of the Lobe Rangers, an advocacy group that campaigns for stronger government action on environmental toxins.

“This wave of momentum and energy came in. But we need to actually turn it into something meaningful with real legislation,” said Smith, an independent voter. “That’s what we’re interested in — getting the public wound up enough where they’re willing to vote.”That the state’s Republican Party has emphasized environmental issues this election speaks both to the perceived scale of the problem and the shifting political coalitions.

“It used to be a kind of liberal, tree-hugger type thing,” said James Hepp, another Lobe Rangers founder and a Republican. “It had that stigma where if you talked to any environment, you were a tree hugger, but now I think you’re just an informed citizen trying to do what’s best.”Many Iowans who spoke to CNN credited the momentum to the MAHA movement, which threw its support behind Lahn, powering his surprise primary victory over the Trump-endorsed GOP Rep. Randy Feenstra.

MAHA Action, a political advocacy group run by longtime Robert F. Kennedy Jr. ally and book publisher Tony Lyons, put $1.5 million towards Lahn’s campaign, and boasts that he was the PAC’s first 2026 endorsement.

“MAHA was the first to believe in Zach Lahn, and the Iowa Republicans proved us right,” Lyons said in a statement. “November is where we prove we can win.”Yet there is distrust over the party’s commitment. Lahn has had to wrestle with GOP action in Washington, where the Trump administration ordered more domestic production of pesticides and rolled back a host of environmental regulations.

“I was one of the first people to come out and say that this was the wrong move to sign that executive order,” on more US pesticide production, Lahn told CBS’ “Face the Nation” this month. “I think that if we could give the president the advice on that, that he would understand that better.”But David Murphy, a MAHA-aligned Democrat who supported RFK Jr.’s presidential run, says he’s skeptical of Lahn because of the disappointing Republican record on MAHA under Trump.

“I fundamentally think that the Trump administration and Republicans have screwed up a major opportunity that RFK Jr. endorsed,” said Murphy, a fifth-generation Iowan who now works on Jones’ agriculture secretary campaign.

In one of the most competitive Senate races in the country, allies of Turek —who was born with Spina Bifida linked to his father’s exposure to Agent Orange in Vietnam — have raised the subject to attack his Republican opponent.

“Across America, cancer rates are going down, but in Iowa they’re going up. As a doctor, I cannot ignore what is happening,” says Dr. Selden Spencer of Huxley, Iowa, in an ad from a Democratic super PAC with nearly $3 million spent in airtime since September. It goes on to criticize Hinson for accepting campaign contributions from accused polluters. Hinson’s campaign did not address the claims in the ad when asked.

But this week, she joined with Democratic Rep. Hillary Scholten of Michigan to introduce legislation aimed at improving access to early detection cancer screenings.

“So many Iowa families have been touched by cancer, including mine. Iowa’s rising cancer rates are unacceptable, and we have to do everything we can to reverse this trend,” Hinson wrote on social media.

Republicans are also grappling with internal fractures driven by the MAHA movement, when pro-business and public health interests collide.

One key point of contention is glyphosate — an herbicide commonly known as RoundUp. While many Iowans believe nitrate levels from manure are causing health problems, there are significant divides over the herbicide between farmers and MAHA activists, who say it is also driving cancer rates across the country.

“The reality is that we have all had a lot of exposure to glyphosate,” said Smith, “as a lot of farmers have.”Disagreement over the chemical has created a dividing line that has alienated farmers — many of whom say it is necessary to keep millions of crops safe through each farming season — from the broader MAHA message, he said.

The science on glyphosate and health risks is far from definitive. The Environmental Protection Agency is undergoing a routine review of its safety this year, but the issue has been supercharged by Kennedy, who has a history fighting broad use of the pesticide.

Reflecting the internal divisions, the Republican candidate for Iowa agriculture secretary, Mike Naig, has criticized Lahn, his party’s gubernatorial candidate, on the subject.

“This is more complex than what some want to make it, and I think you’ve got some who have decided it’s a political issue. And I think that can be very dangerous,” he said in August.

Amid fissures on the right, Democrats are leaning into the issue. It’s “unsurprising that one of the stronger MAHA movements” emerged in Iowa given the incidence of cancer there, said Lauren French of Senate Majority PAC, the Democratic super PAC behind the ads in the Turek-Hinson race.

But while the burgeoning movement is “leaning more Republican at the moment,” she sees an opening. For Democrats, talking about Big Ag chemicals “fits into the larger issue of corruption,” she said, nodding to another major voter concern this cycle.

“The problem for Republicans in Iowa, is that they have a long history of being on the wrong side of this. They chose to align themselves with the companies that are doing the poisoning of the water,” she said.

Some Democrats, however, also face scrutiny. Lahn has accused Sand of being beholden to agricultural interests and accused him of taking money from a donor “caught polluting your drinking water” — claims vigorously contested by Sand’s campaign.

In the closing weeks of the race, Sand has held a roundtable with cancer survivors in West Des Moines, discussing his plans to tackle the problem and pledging to “appoint a Cancer Task Force.”

“Rob Sand is the only candidate in the race with a plan to address those concerns,” said Emma O’Brien, the deputy campaign manager. “Meanwhile, Zach Lahn supports the One Big Beautiful Bill, which cuts funding for cancer research, and wants to ban mRNA vaccines, which have been found to be a promising treatment for cancer.”Lahn’s campaign did not reply to CNN’s requests for comment.

A poll released this week from the Cook Political Report, in partnership with New River Strategies and GS Strategy Group, has Sand with a clear lead over Lahn in the contest for governor. A CNN poll of polls in Iowa this week shows the Senate race in a dead heat.