Until someone comes up with a vehicle that people living in rural areas can use, where its not unusual for their daily commute to be 60 miles or more, its not going to happen. Lots of places in the U.S. are not suitable for wind power (not enough wind), solar power, geothermal, etc. Yes, it would be wonderful to spend the $400 billion here, but what would we do in the meantime while all these wonderful ideas get invented, perfected, and finally cheap enough and practical for the whole country to use?
Go back to living in caves, live like ascetics of India?

Well, we should have thought of that while we were busy living the American Dream.

If the mortgage companies weren't so busy taking away our homes and land, we could start a program to get people farming their own land instead of just wasting time mowing it.

Innovation until now has been left pretty much to the military and high tech areas(our taxes). The common man, if given the time and resources could come up with some great solutions to today's problems. This is a mostly untapped area of our lives.