Following years of debate, the EPA said earlier this month it will study the possibilities of cutting the amount of ethanol in the United States' gasoline supply.
Since 2007, the Renewable Fuel Standard (RFS) has required growing amounts of ethanol to be blended into U.S. fuel supplies, with E10—a mix of 10 percent ethanol and 90 percent gasoline—now effectively standard across the country.
However, the Trump Administration's apparent plans to curb the biofuel, today still largely based on corn as a feedstock, has stirred the ire of a powerful politician in corn-rich Iowa.
Senator Chuck Grassley [R-IA] lamented the EPA's decision to study a reduction in ethanol-blended gasoline.
Grassley said the decision would "drastically undermine" the production of biofuels in the state of Iowa and reflected "contrary statements" made by then-candidate Donald Trump, The Washington Post reported last week.
President Trump defended the biofuel industry throughout his campaign and called out rivals over their support for big oil companies.
Today, the total amount of ethanol blended into gasoline hovers around 19.28 billion gallons a year, but the EPA's proposed reduction would bring the level down incrementally, to 19.24 billion gallons.
However, the total amount of corn-based ethanol fuel would remain at 15 billion gallons, according to the EPA.
President Trump reiterated his commitment to biofuels at a campaign-style rally in Iowa earlier this year, but the industry doesn't command the support it did 10 years ago when the Renewable Fuel Standard was passed.
In addition to the EPA's proposed reductions, the oil and gas industry has pressured the current administration to cull the RFS and argues biofuels add to the cost of refining fuels.
According to Grassley, his meetings with Trump cabinet members have been "generic." Grassley and 37 other senators wrote to EPA head Scott Pruitt urging him not to cut, but to increase, the amounts of biofuels required by the RFS.
The senator was clear to criticize Pruitt and not President Trump, however, suggesting that Pruitt has taken the lead on the potential reduction in biofuel production.
Before heading the EPA, Pruitt sued the agency more than a dozen times as attorney general of Oklahoma, urging courts to prevent the EPA from enforcing legal emission regulations.
Pruitt and the state's powerful fossil-fuel producers lost the majority of those cases, but Trump nominated Pruitt to be the fourteenth Administrator of the agency he had repeatedly sued.
Ten years ago, in an era of rising gasoline consumption and higher gas prices, Congress pegged ethanol and biofuel production as the way to reduce dependence on imported oil for road transport.
Many automakers engineered their internal-combustion engines to support blends as high as E85, or 85 percent ethanol, and such "flex-fuel vehicles" earned additional credits under the Corporate Average Fuel Economy regulations.
The effects of the recession, a long plateau in total miles driven, and stiffer CAFE requirements starting in 2012 mean that gasoline consumption peaked in 2008 and fell for almost 10 years thereafter.
That, in turn, means that the numeric volumes of ethanol required under the RFS are being applied to gasoline supply that hasn't grown but in fact lessened.
The EPA has opened a public comment period over its potential reduction of ethanol levels; it must submit final proposed production volumes by November 30.