This is one issue where a good number of people all across the political spectrum can agree. Ethanol is a disaster. Here's a 2009 article on the topic: http://www.popularmechanics.com/cars/hybrid-electric/a2422/4237539/

The bottomline: "a huge hidden tax on consumers, with benefits flowing to the politically connected" That's what ethanol has always been about.

On a related note, what does the US do with much of that excess corn? It ships massive sums to other countries, which ruins livelihoods, forcing residents of those other countries to seek refuge elsewhere (migrants who are then attacked for doing what anyone else in their shoes would do). What enables the US to flood other countries with cheap, subsidized agricultural products? So-called "free" trade agreements such as NAFTA.