In a speech last month to farmers in Texas, President Donald Trump won applause as he talked up recent U.S. trade agreements. When he tried to boast of his administration’s ethanol policy, however, he was met with silence. Iowa swung sharply to Trump’s Republicans in the 2016 presidential election, but Democrats hope anger over a relaxation of rules mandating use of ethanol by U.S. refineries could put the corn-producing state in the win column this year. “I think they haven’t solved the farmers’ problems in terms of ensuring farmers will have a consistent market for the ethanol that they produce,” said Wayne Moyer, a political science professor at Grinnell College in Grinnell, Iowa. “It’s a sore spot.” Federal rules require refineries to blend 15 billion gallons of conventional biofuels like ethanol, which is made primarily from corn, into the nation’s fuel pool every year. Refiners […]