Why do you subsidy ethanol with $5 Billion per year from the Treasury ?

Why do you subsidy ethanol with $5 Billion per year from the Treasury

With basic food prices rising, we want cheaper grain  food products, not some some expensive additive for gasoline.  Putting ethanol in your gas tank in effect drives up food prices.

From the latest Obama tax proposal..................
Among the energy tax provisions added was an extension of the current 45-cent per gallon subsidy for ethanol, at a cost to the Treasury estimated at nearly $5 billion. The issue is of particular interest to lawmakers from Midwestern states with grain crops.