If US like the rest of the world, make trains popular and brings the costs down for trains and actually has more connectivity. The distance will quickly not become a problem. Like I said all we need is a sleeper coach, and we just have comfortable nap to the destination over night. India is able to transport millions of people in 2500+ KMs routes a day, you are looking at the people who are forced to pay and travel in those forsaken airliner comfort. Trains will only bring more people together when they connect more and make it affordable.
2500 km == 1500 miles, or the driving distance from NYC to Dallas. If you wanted to go from Dallas to Los Angeles, that’s another 1400 miles (2300km).
Trains have hauled passengers for about 200 years. I’d love them to increase in popularity and availability, but suspect that there won’t be huge change if it hasn’t happened by now.