OK, a few myths seem to need busting.
1. It takes more than a gallon of gas to make a gallon of corn ethanol. It appears this was once true, in about 1973. Today, the figure is much better due to improved ag yields and better alcohol production methods and appears to be a net gain per gallon. But more importantly, such rhetoric ignores the cost of converting OIL to gas. Pumping the stuff out of the ground half a world away, transporting it via supertanker, refining it, transporting it to gas stations all combined probably uses close to one gallon of gas per gallon delivered too! How is it worse to expend energy transporting gas across the world than growing and refining alcohol right here?? Corn clearly isn't the long term answer, but if it STARTS the process of getting ethanol out there in good quantities and results in more cars capable of using it, that is a GOOD thing. Free markets will eventually result in more efficient means of ethanol production than corn (switchgrass is an intriguing example).
2. I can convert later. Not really. It is VERY cheap to modify the design of a car to run on E85. It is just some programming and fuel line materials. It is very EXPENSIVE to retrofit a car to E85. Look at the option cost to get E85 on a Chevy Impala or Suburban. Practically free. Why NOT make all cars compatible? What's the downside (besides the few bucks)? If the whole fleet has the capability, we will have more options if Iran gets all fiesty (or Venezuela, or Nigeria.....)
3. Water is a great energy source.
No it isn't. You can MAKE hydrogen out of water, but it requires more energy input than you can get back out of the hydrogen later. This is basic conservation of energy stuff folks. You cannot create or destroy energy, only change its form. And every time you change its form, you loose some in the form of heat loss. This is different from the ethanol efficiency argument because ethanol is fundamentally solar power. The solar energy input goes into making the plant. We then convert it to ethanol and extract it. Unless you use solar power to make water into hydrogen (currently MUCH pricier than ethanol), you will use more energy than you make.
4. Ethanol drives up the price of food. Perhaps it does. Is that an awful thing? I'm not so sure. I went to school in Wisconsin and the farms kids I knew came from families always on the edge of bankruptcy (except those close to urban areas who could sell land to developers). Perhaps it's about time farming became a viable living again. Maybe it reduces the amount of surplus corn we have to ship as aid to poor nations. Such shipments have arguably bankrupted local farmers in those nations and resulted in a self-perpetuating cycle of famine. Maybe making farming a viable living there would be a good thing too. Worth thinking about, anyways.