As I understand, farmers have moved from food corn to a breed of corn for Ethanol, resulting in greatly increased prices for food corn due to lower supply and higher demand. If ethanol subsidies were cancelled, farmers would return to food corn, jobs would remain static and supply would increase in the food corn sector.
Commodity corn is animal food. The commodity corn supply and the acres devoted to it have increased to accommodate fuel ethanol demand and commodity corn prices are where they have historically been - around the cost of production. Hybrids for fuel don’t really change the commodity corn market.
The kinds of corn used for immediate human consumption have always been a specialty crop. Big users like Frito-Lay have it grown for them under contract.