For decades, many presidential candidates campaigning in Iowa have made sure to offer their loud support for ethanol — the fuel made from corn.
Ethanol is an important industry in Iowa. The state is the top producer of ethanol in the nation, accounting for 28 percent of national production, according to the U.S. Energy Information Administration.
But this election cycle, ethanol is not the campaign force it once was.
Take the contrast between George W. Bush's 2000 presidential campaign and the current campaign of his brother, Jeb Bush.