contributed photo A flag flies at the Southwest Iowa Renewable Energy ethanol facility prior to a visit from President Donald Trump in 2019, in Council Bluff.

Republican candidates for the presidency have fawned over farmers this caucus season as they’ve courted voters in Iowa — the nation’s top producer of corn, eggs and pork.

The candidates often talk in platitudes about their support for Iowa agriculture and paint themselves as farmers’ best friends.

“I’m proud to be the most pro-farmer president that you’ve ever had in your life,” former President Donald Trump told supporters during a campaign stop in Council Bluffs in July.

None of the candidates has suggested that farmers be forced to implement costly measures to help the environment. To the contrary, the candidates rail against federal regulations that pertain to agriculture, especially those that seek to protect the nation’s streams.

“I will prevent both federal and state overreach from obstructing our agricultural industry,” Florida Gov. Ron DeSantis wrote in the Des Moines Register.

The lone agriculture issue to cause serious contention among the candidates is ethanol, which Iowa also leads the nation in producing.

Ohio businessman Vivek Ramaswamy said he supports the ethanol industry, but when he was poised early this month to announce his forceful opposition to using eminent domain to build carbon dioxide pipelines — and to even question their purpose — the Iowa Renewable Fuels Association released a scathing critique of the candidate. The association called him a hypocrite for his support of an oil pipeline and lack of support for pipelines that might benefit ethanol producers and farmers.

Ethanol has, on the whole, been a rallying point for the candidates. More than half of the state’s corn is used to produce the fuel — bolstering demand for the crop and the price per bushel it fetches. And the candidates have supported its use in combustion engines as an alternative to electric vehicles, which are largely disdained by Republican voters.

A Gallup poll in March found that 71 percent of Republicans would not consider owning an electric vehicle.

But the unwavering support for ethanol among the candidates was not initially clear. DeSantis, when he was a congressman representing Florida in 2017, supported an end to the Renewable Fuel Standard, which mandates a certain amount of ethanol be blended with gasoline each year.

Trump has taken repeated shots at DeSantis because of it: “If he had his way the entire economy of Iowa would absolutely collapse,” Trump said in July.

DeSantis has reversed course on the issue and said recently he would not seek to end the biofuels mandate.

The candidates have expressed support for the year-round sales of E15, a gasoline blend that is 15 percent ethanol. In some states, including Iowa, the gasoline that is blended with ethanol is more volatile, and the E15 that is created with it does not meet federal fuel standards in the summer that are meant to limit air pollution caused by evaporation.

“Why is government telling you what months you can do it?” Nikki Haley, a former ambassador to the United Nations, said during a campaign stop in Altoona.

Trump scored points with the ethanol industry in 2019 when his administration decided to allow the widespread sale of E15 during summer months, but the rule change was struck down by an appeals court that said only Congress could authorize it. He also drew the ire of ethanol advocates when his administration granted waivers to fuel refiners that exempted them from Renewable Fuel Standard requirements.

Trump holds a commanding lead in Iowa, according to a recent Des Moines Register/NBC News/Mediacom Iowa Poll. He is the top choice of 51 percent of likely Republican caucusgoers. DeSantis and Haley are a distant second and third, with 19 percent and 16 percent. Ramaswamy has the fourth-most support at 5 percent.