Who do you think??
Farmers benefit least of all and remember farmers involved in livestock production saw their feed bill more that double.
I don't have hard data at hand to support this but here are the major benfactors imo:
1. Ethanol producers who couldn't operate without huge subsidies and grants from the federal government. There may be some smaller startups but I would guess the linon's share of those moneys go to some of the girant corporations already involved in the energy business. Investors in those businesses who were in the know that an ethanol mandate was in the works.
2. Huge international corporations such as ADM, in the food production and wholesale grain businesses and well positioned investors in the futures grain markets. Some who had large stores of grain they had bought cheaply and were able to empty their silos at the new higher prices being paid because producers of ethanol had to buy because of the mandates.
3. Some politicians who convinced the people of their respective states that said politican had done them a big favor.
4. Middle men, commodities traders etc etc.
From about a year ago.
Then too, it is important to point out that politicians couldn't really make the claim that ethanol mandates would significantly reduce CO2 emmission so they made the claim it would reduce dependence on foreign oil.
If making the US less dependent on foreign oil was the motivating factor, it makes a lot more sense to drill domestic oil fields and built our own refineries than to isssue ethanol mandates.