United States High Speed Train?

For decades the United States has been toying with the idea of building a network of high speed train routes throughout the country. This system would be similar to the one that operates in Europe. Many oppose the system because of the cost to build it; however, I feel that some of the most innovative and economically useful public projects have also come at costs that seemed high at first. Consider for example the interstate highway system. This project began in the 1950's and parts are still under construction today; it was expensive, but it helped bring the United States to a position of power among world economies.

Here is a proposed map of the train network in the United States.

Although this map is visually appealing, it may not be fully realistic. Many areas along the red and blue routes would need to be eliminated because these areas do not have the population density to support ridership. 

A network of high speed trains would serve a wonderful need in society. Trips that are between 100 and 600 miles would be ideal to make by train. These trips would be too long many people to tolerate in a car, but going through security for a flight of this distance could take as long as the flight itself. Trains would provide high speeds without needing to wait in extensive check in lines. This could revolutionize medium-distance travel in the United States, encouraging an increase in business and leisure travel, particularly in mega-regions such as the Northeast or South-Central California.