Senator Ted Cruz, the born-in-Canada candidate seeking to become the Republican Party's candidate for president, says he would scrap the subsidies for ethanol production.
And Cruz came in first in balloting in Iowa, home to much of the ethanol industry.
But Iowa Senator Ted Grassley says that even if he becomes president, it's not likely to happen because it would take legislation passed by the House of Representatives and the Senate to end the subsidies.
The chief "subsidy" is a requirement that a target volume of ethanol each year be added to gasoline.
In Canada the requirement is a percentage of ethanol in gasoline and it varies by province because the mandates are both federal and provincial.
But Cruz wants to scrap far more than the ethanol subsidy. He wants to scrap all energy subsidies - for oil, for gas, for coal, for wind and solar power, everything.
He says "Washington shouldn’t be picking winners and losers.
"That’s why my tax plan ends all energy subsidies and mandates.
"No Washington favouritism for oil and gas, for wind, for solar, or for anyone else.
"We should phase out the Renewable Fuel Standard, end all energy subsidies, and ensure a level playing field for everyone.”