The mandate is a certain amount of ethanol has to be sold in the gasoline market. Only certain areas require reformulted gasoline that contains ethanol.
So they do mandate the use of ethanol, but the feds do not mandate every gallon contains ethanol.
For the past year or so one of our chains is selling premium without Ethanol. I have been using it exclusively and am getting almost a full mile per gallon better mileage...plus the snowblower and lawn mower love it.