ALTOONA, Iowa (AP) — Iowa’s governor and congressional delegation are trying to shore up political support for ethanol, which is slipping as the nation produces more of its own oil. Gov. Terry Branstad is pushing to reverse the Obama administration’s proposal to cut the required amount of ethanol in the nation’s fuel supply. Almost half of Iowa’s corn crop goes to manufacture the grain alcohol, which is blended into gasoline.

Presidential candidates traditionally supported the federal mandate when they campaigned in Iowa, but many now say it is no longer justified. Environmentalists have complained about impact of expanded corn production. But Branstad says the federal mandate is important to Iowa farmers with corn prices low.