The Trump administration is holding off any major shift in ethanol policy, announcing last week that it would maintain the blending mandate for ethanol and other biofuels near current levels in 2018.
Ethanol wins a round in its battle with oil - Houston Chronicle

In 2015, when Rep Ron DeSantis offered an amendment to repeal the ethanol mandate, he was told by the Congressional Budget Office(CBO) that his effort would run amok budgetary procedures because it would increase the deficit by decreasing tax revenue. How so? By alleviating consumers from purchasing diluted fuel and allowing them to actually fill up their tanks with unvarnished gasoline, motorists wouldn’t have to refill their tanks as often as they do now. That would result in less revenue for the government!
This week Trump tweeted that gas prices are low ,but he wants to see them go lower. The best way to do that would be to allow the consumer to purchase gasoline instead of a 10-20% mix cut with corn ethanol.