Donald Trump and Ted Cruz are escalating their feud in Iowa.

It makes sense that the gloves would come off between the Republican presidential rivals as the clock ticks down to the start of primary voting season. Animosity between the candidates boiled over on the national stage at last week’s Republican primary debate. Cruz denounced Trump for his so-called “New York values,” implying that the real-estate mogul just might be a bleeding-heart liberal. Trump shot back, suggesting that Cruz’s Canadian birth could disqualify him from the presidential race.

Now, the Trump-Cruz fight is taking a more parochial turn. Trump is attempting to gain an advantage over Cruz in Iowa by affirming his support for the ethanol mandate, a popular policy in the early-voting state. On Tuesday, Trump called for an increase in the mandate, The Hill reports. The mandate is part of the Renewable Fuel Standard, a federal program that requires renewable fuels, such as ethanol, to be blended with gasoline each year. Iowa’s robust corn industry loves the policy since ethanol production creates a market for Iowa corn. But that hasn’t been enough to convince Cruz, who supports ending the mandate in a five-year phase-out. That view led Iowa Republican Governor Terry Branstad to jump into the fray on Tuesday, saying that he wants to see Cruz defeated. Cruz “hasn’t supported renewable fuels, and I think it would be a big mistake for Iowa to support him,” the governor declared.

The split between the candidates reveals the different political calculations at play. It’s common for presidential candidates to pledge support for the mandate in Iowa as a way to curry favor in the state. Trump’s rush to embrace the policy speaks to just how much he wants to win Iowa. Trump and Cruz are running neck and neck in Iowa polling, and both are vying to take the top spot in the state caucus, now less than two weeks away. If Trump can turn the ethanol mandate into a wedge issue, it could give him an edge over Cruz, who has been steadily gaining ground in Iowa. Trump’s excitement over Branstad’s denouncement of Cruz was evident on Twitter, where he wrote: “Wow, the highly respected Governor of Iowa just stated that ‘Ted Cruz must be defeated,’ Big shoker [sic]! People do not like Ted.”

The fact that Cruz is running away from the mandate, however, suggests a decline in Iowa’s political clout. Backing the policy puts Republicans in an awkward spot since it’s a top-down, government mandate. Yet GOP presidential contenders who have supported the requirement in the past have tended to fare well in the state. Rather than embrace the policy beloved by Iowans, however, Cruz appears to be doubling down on his bona fides as a conservative purist who is opposed to government mandates of any kind. On the national stage, that could help Cruz attract conservative voters. But the strategy likely reflects a calculation that despite Iowa’s long-vaunted status as the first state to cast votes in the presidential primaries, its influence has diminished. In an era where social media and wall-to-wall cable-news coverage makes it easier for candidates to take their pleas for votes directly to a national audience, special interests in early voting states may not matter as much as they once did.

Like any good politicians, Trump and Cruz are using their Iowa stands to advance a bigger-picture narrative.  Trump is casting his support for the mandate, which benefits America’s renewable-fuels industry, as evidence that he’ll do whatever it takes to “Make America Great Again.” “Energy independence is a requirement if America is to become great again,” Trump said Tuesday. Cruz, meanwhile, is holding up criticism over his opposition to the policy as evidence of his outsider status. The senator suggested on Tuesday that Branstad’s repudiation shows that the political establishment feels threatened by his candidacy. “It is no surprise that the establishment is in full panic mode,” Cruz said, reacting to the governor’s comments. “We said from the beginning that the Washington cartel was going to panic more and more. As conservatives unite behind our campaign, you are going to see the Washington cartel firing every shot they can.”

The Iowa governor’s concern is understandable. If Cruz manages to win Iowa without siding with the state’s high-profile lawmakers and a powerful industry, it could send a message to future candidates that they don’t need to support the mandate to emerge victorious in Iowa. More troubling for those invested in Iowa’s political clout: A Cruz win would signal that the state’s power to shape the positions of presidential candidates is definitely in decline.