Donald Trump attacked Ted Cruz for not supporting ethanol subsidies. He said in Iowa on Friday, "Oil companies give him a lot of money, so he's for oil." The thing about oil and gas is, it doesn't require big subsidies, because it's the cheapest and most efficient form of fuel for cars. Ethanol, on the other hand, does require big government subsidies, because it is highly uneconomical. Ethanol is much more expensive than oil and gas and, gallon for gallon, produces much less energy than gasoline. That's why the government has to hand over billions in subsidies to big agri-businesses...