LACONA, Iowa (AP) – Cracks are appearing in President Donald Trump’s support from Midwest farmers. His trade war with China has already scrambled global grain markets, but now corn farmers are up in arms over Trump’s decision to allow dozens of oil refineries to skip blending corn-based ethanol with gasoline. The head of the National Corn Growers Association, Nebraska farmer Lynn Chrisp, says frustration with Trump has boiled over. One Iowa farmer, Randy Miller, sees the ethanol waiver as a stab in the back.