I threw Monsanto into the mix because they really push their Processor Preferred® corn for ethanol,
From Knowledge Problem:
The House of Representatives budget battle has produced a few shots at the ethanol industry, including “Sullivan of Oklahoma Amendment No. 94,” a proposal to prevent the EPA from taking steps to encourage the sale of gasoline with higher ethanol content for use in newer cars. The amendment succeeded, 285-136 (12 not voting), and the resulting map of yeas and nays is so predictable, unsurprising, and boring that even as I am posting it I wonder why I bother.
Anyway, here is the map of the vote (blue is a vote opposing ethanol, red a vote favoring ethanol), followed by a USDA map showing corn production and ethanol plants: