The Trump administration plans to appeal a court ruling that said the Environmental Protection Agency broke the law by exempting dozens of small oil refiners from their biofuel blending obligations, Reuters reported last week. 

Renewable fuel supporters sharply criticized the potential appeal, saying it would violate the president’s promise to ensure 15 billion gallons of ethanol are blended into the fuel supply under the Renewable Fuel Standard (RFS). 

“If not changed, this would go down as one of the worst decisions I’ve seen in 20 years of...