This has been a scam, or another idiotic greenie idea, at best...from word go. Just a vote buying scheme.

"Federal law requires the EPA to assess the environmental impact of the fuel standard every three years, but the new report, issued in July, was four years overdue. According to David DeGennaro with the National Wildlife Federation, the report documents millions of acres of wildlife habitat lost to ethanol crop production, increased nutrient pollution in waterways and air emissions and side effects worse than the gasoline the ethanol is replacing.
"In finding that the Renewable Fuel Standard is having negative consequences to a whole suite of environmental indicators,” DeGennaro said, “the report is a red flag warning us that we need to reconsider the mandate's scope and its focus on first-generation fuels made from food crops.”

Obviously, I disagree with Trump on this...bigly! Somehow, though, I don't think he cares what I think. Oh, the humanity!

Alas, the mandate is so popular with corn farmers in Iowa, home of the first round of presidential nominations, that President Trump (and other politicians) that they not only maintain the mandate, President Trump just last week “told an audience in Iowa that he was "very close" to having EPA issue a waiver to the Clean Air Act to allow year-round sale of E-15.”