An Ideal Location for High-Speed Rail in the United States

Dallas-Austin-Houston

There's about 400 flights a week between these three cities. The cities are about 200-300 miles away from each other. The environment there is largely flat and seldomly sees freezing temperatures. Creating real competition with the airlines would be beneficial to all as it would force airlines to make it a better experience or a better price.

That's before considering car traffic. Even with enormous amounts of land dedicated to some of the widest highways in the country, they still have horrible traffic issues. Trains could help alleviate that.

Besides the automobile and airplane lobbies, what am I missing here that makes it an impossibility?