Iowa kingmakers in the party such as Sen. Chuck Grassley want the Republican presidential nominee in 2016 to champion ethanol.

That’s a problem for Cruz and to a lesser extent for Paul, who are both crisscrossing the state this week in advance of possible campaigns for the presidency.

Cruz has introduced legislation that would repeal the renewable fuel standard over the next five years. The standard mandates that gasoline contain 10 percent ethanol by volume.

“I believe we should pursue an all-of-the-above energy policy and that Washington shouldn’t be picking winners and losers,” he said.

Cruz argues the fuel standard has proven unworkable and costly, according to a summary of his bill.