[electricron]

I'm not so sure all their calls are correct, but they did make one important call that California HSR did not. Start with connecting your two largest cities in phase 1.

it was to their advantage that the two largest cities are only 118 miles apart - while in California they are 397 miles apart using Highway 99.
If you are connecting the two largest cities in the entire country, New York City and Los Angeles are 2,774 miles apart using the shortest highways.

The entire HSR2 project includes construction of 335 miles of new HSR corridors, and will visit 8 of the UK's largest cities. Just LA to SF requires more tracks. Building HSR to the 8 largest US cities will require thousands of miles of new HSR corridors.
Here's a list of the 8 largest metros in the USA;
New York City, Los Angeles, Chicago, Dallas-Fort Worth, Houston, District of Columbia, Miami, and Philadelphia.
NYC, LA, and Chicago on the 2,774 mile corridor mentioned earlier intercontinental route.
NYC, Philadelphia, D.C. and Miami on a second 1,276 mile corridor on the east coast.
A third corridor to the two Texas cities would be needed, from Kansas City on the intercontinental route, Dallas is 508 miles away, and Houston an additional 239 miles, for a subtotal 747 miles of new HSR line.
At a minimum, a national HSR network reaching at least the 8 largest metros in the USA would require 4,797 miles of new HSR corridors. To put that in perspective, 4797 / 335 = 14.319, or 1431.9% more.