By Ian Brimcombe
BBC News, Chicago
The United States produces almost half of the world's maize, or corn, harvest - most of it in the Midwest. It is used for food, animal feed and, increasingly, it is converted into ethanol fuel.
With the mid-term elections around the corner, Midwestern leaders from both the Republican and Democratic Parties are talking up the need for greater investment in ethanol production and distribution.
Even George Bush has spoken in favour of ethanol
"Home-grown fuels help make us less dependent on imported oil, create jobs, help farmers and protect our environment," says Illinois Governor Rod Blagojevich.
"By harnessing Illinois' own rich natural resources, we can become the first state to replace 50% of our fuel supply with home-grown alternatives like ethanol by 2017."
Mr Blagojevich is promoting a fuel called E85, an 85% blend of ethanol and 15% unleaded petrol.
It is slightly more expensive than ordinary petrol and does fewer miles per gallon.
One of the region's biggest ethanol plants is run by North East Missouri Grain, in the neighbouring state of Missouri.
Standing on the factory floor, surrounded by giant tanks of fermenting corn mash, NEMG general manager Steve Burnett explains how ethanol is made.
Mr Burnett runs one of the country's largest ethanol plants
"The corn is first ground into grain and then the corn's starch is fermented into sugar and eventually distilled into ethanol."
The ethanol made at the plant can be mixed with 90% petrol to make a fuel called E10, which can be used by any vehicle and is sold at the pumps all over the Midwest.
But E85 can only be used by a hybrid, flexible fuel vehicle, so the support of the American car industry is essential to E85's success.
There are currently more than four million of these vehicles on America's roads and the number looks set to increase.
"Ford, along with some of the other US auto manufacturers, has committed to increasing flexible fuel production by 250,000 vehicles," says Mary Culler, a spokeswoman for Ford.
"So there's no doubt you're going to see an increase in the types of vehicles available to consumers."
Winning customers round
But if E85 is going to be a viable alternative to petrol, people have to be able to buy it.
And, so far, that has not been easy. Fewer than 750 of the more than 180,000 fuel stations across the country sell E85.
The Stephenson Drive Qik-n-EZ station, near the Illinois capital, Springfield, is one that does.
It is located along the recently unveiled Midwest ethanol corridor, a stretch of interstate running from Chicago to Kansas City where motorists can get E85 fuel along the way.
"At the beginning there was a lot of doubt about E85," says assistant station manager David Horsley. "People were asking 'What's it going to do to my engine?'"
"But as time has passed, more people are using it. Now we have a very good market for E85 and it is growing."
With elections coming up, E85 is an issue that will likely continue to find its way into the speeches of politicians throughout the Midwest.
But unless the infrastructure improves to make the fuel more readily available for sale, and until more people invest in flexible fuel vehicles, even here in ethanol country, the prospect of E85 seriously competing with petrol at the pumps seems a long way off.