Some what related to ethenol. Since it lowers your fuel economy, you need to burn more fuel = more emissions, aka pollution, into the atmosphere to arrive at your destination.
Since we now produce more oil than Saudi Arabia, and through good old American ingenuity, effectively have access to known oil reserves to power us into the distant future, wouldn't it make sense to try and mitigate potential damage to internal combustion engines. Thats not even mentioning all the energy burnt to plant, harvest and distill the ethenol.
At least lets use more efficient fuels (gosh we have plenty) until a more viable alternative is discovered. Just sayin'