It might make sense from San Diego to Los Angeles and from Sacramento to San Franciso.
A limited high speed rail system could be built very cheaply.
But unfortunately that only underscores why the rest of it isn’t really necessary and the politicians won’t hear it.
Sac-San Fran, nowhere near the population density.
LA-SD and even throwing in Tijuana, no. Shorter yes, but you’d have to have 60 million people for it to make money.
All the people who knew how to run a railroad are dead. Any of them could tell you that passenger lines have almost never been profitable. Were it not for freight and the mail, the railroads could never have afforded to run passenger cars.