^ I don't agree with full nationalization. Such a dramatic socialist gesture (made even more by how exponentially more operating private railroads there were in the US verses Europe at the time) would have never been acceptable by that political climate nor this one. In theory what I DO think should have been done was the "nationalization" of the corridors and ROW of private railroads. As we know, the railroads in many cases were essentially given the land to build corridors, facilitated through eminent domain and land grants by the federal goverment - see the
Pacific Railroad Acts for instance. This ribbon of privatized right of way traverses the country and the very fact that it has remained private property, IMO has prevented an abundance of critical rail transport projects coast to coast because of the "sovereign in tone" objections of the railroads over interoperability concerns. It makes much more since for the ownership of the infrastructure to be nationalized or socialized, whatever word works for you, and leased to a potential mix of privatized freight railroads and private or public passenger services. Since you mentioned SNCF as a model, this scenario is very similiar to how
RFF operates - especially now with its current and future agreements with German DB and Spanish Renfe, etc. Nationalization would put an end to the constant objections of the private freight railroads to sharing tracks (Amtrak being the only exception, and that took an act of congress and a 40 year long contentious relationship continues) and looking into the future building new parallel dedicated passenger tracks in existing ROW's, something the private railroads currently absolutely reject. BTW, the excellent book
Waiting on a Train by James McCommons has a chapter on nationalization. The whole book is required reading for anyone that seeks to understand the current embarrasment that is the US passenger rail system.
The way I see it this is the only way to really speed the development of a truly European grade system through the US outside of massive from-the-ground-up ventures like CAHSR that require huge ROW land acquisition. Will it happen? Probably not. It would take a major shift in political ideology in Washington, or even the state level, to be inclined to put forth quasi socialist European style policy proposals like this, even if only in the focused field of rail transportation. But they already have an excellent example of such a "nationalized" experiment to look to for bold inspiration - the interstate highway program.