WASHINGTON (AP) — The Obama administration's latest plan on ethanol, the corn-based renewable fuel, probably will not have a major effect on pump prices, but could have political reverberations in Iowa and other farm states in the 2016 presidential campaign. Under the proposed rule announced Friday, the amount of ethanol in the gasoline supply would increase in coming years, just not as much as set out under federal law. That approach drew criticism from ethanol and farm groups that have pushed to keep high volumes of ethanol in gasoline. Democratic presidential candidate Hillary Rodham Clinton has called for a robust...