The future of public transportation exists in seminal projects all around us. Every thing from sisal bodied electric cars to moving slide walks. They will happen as soon as there is political will to make it happen.
The biggest problem for politicians is not spending money. They can do THAT just fine. That is just a debating point. Its knowing where to spend the money to get the biggest political leverage.
To that end, you must create a grass roots movement to break the back of the present model...it is driving developed nations into bankrupcy just to replace all those bridges! Not to mention the soul crushing horror of the highways deaths and damage.
Your states are as big as European countries. So its not size holding TGV back. (Another red herring debating point) Its the present vested interests. Who got the bail outs? General Motors or the Northern Pacific Railway? Which one moves more people every day, and which one kills a hundred people every day? (see what I mean?
The small university town in Fredicton New Brunswick decided that rather than increase the number of police on the streets to try to keep drunk kids from being, well, kids, they simply issued a heavily subsidised taxi pass (like a bus pass) to the students, and increased the parking fees. Worked like a charm. Reduced the accident rate to nearly zero, and cost much the same as three or four extra constables. A similar E-pass here in Ottawa has had similar results, but has proved to be controvercial. But...thats the kind of thinking we need. Not "well, build bigger roads, more parking areas and put more police on the roads". The problem was dead students and massive downtown congestion on Friday nights. The E-pass fixed that.
Of course, that is not an answer to how to bring TGV trains into the states...it will happen when you can convice these people that they can make a buck on it.
This was in responce to Cerilean Bill's rant about why there was no high speed trains in the US.