Iowa lawmakers and biofuel leaders last week urged farmers and others to keep the heat on the Environmental Protection Agency (EPA) and the Obama administration to back off proposed changes in the Renewable Fuel Standard (RFS).

Also last week, Iowa’s Attorney General Tom Miller said the EPA may not have the legal authority to make changes it has proposed to sharply reduce the required use of ethanol in 2014.

Although the public comment period on the EPA’s proposed changes to the RFS ended Jan....