ethanol may actually make some kinds of air pollution worse. It evaporates faster than pure gasoline, contributing to ozone problems in hot temperatures. A 2006 study published in the Proceedings of the National Academy of Sciences concluded that ethanol does reduce greenhouse gas emissions by 12 percent relative to gasoline, but it calculated that devoting the entire U.S. corn crop to make ethanol would replace only a small fraction of American gasoline consumption. Corn farming also contributes to environmental degradation due to runoff from fertilizer and pesticides.But to dwell on the science is to miss the point. As the New York Times noted in the throes of the 2000 presidential race, ―Regardless of whether ethanol is a great fuel for cars, it certainly works wonders in Iowa campaigns. The ethanol tax subsidy increases the demand for corn, which puts money in farmers‘ pockets. Just before the Iowa caucuses, corn farmer Marvin Flier told the Times, ―Sometimes I think [the candidates] just come out and pander to us, he said. Then he added, ―Of course, that may not be the worst thing. The National Corn Growers Association figures that the ethanol program increases the demand for corn, which adds 30 cents to the price of every bushel sold.Bill Bradley opposed the ethanol subsidy during his three terms as a senator from New Jersey (not a big corn-growing state). Indeed, some of his most important accomplishments as a senator involved purging the tax code of subsidies and loopholes that collectively do more harm than good. But when Bill Bradley arrived in Iowa as a Democratic presidential candidate back in 1992, he ―spoke to some farmers‖ and suddenly found it in his heart to support tax breaks for ethanol. In short, he realized that ethanol is crucial to Iowa voters, and Iowa is crucial to the presidential race.