> There already is high speed-ish rail travel in the Northeast and it's very popular. But, for example, even if you could magically offer 6-8 hour train service between New York and Chicago, relatively few people would take it given that flying would be significantly faster.

Texan living in NYC here. I disagree. I would happily pay to take a 6 hour train to Chicago over a flight anyday. LGA/JFK are nightmares to book last minute flights and high-speed rail is a favorable experience to flying sometimes.

In contrast, there's no "useful" rail network in Texas — at all. If there was a rail network, like the single-high speed line proposed between Dallas and Houston, it would totally dominate and disrupt. People fly to/from cities in Texas all the time.

There are many many cities that would benefit from a rail network because the cost would be considerably lower than flying. If you build it, they will come.