Most rail line are serviced by private company nowadays, most Port Authority have given their operation license to lower the cost/production management. The main reason why railway still earn their bucks is not passenger transport by the way, it's to move material around the US with hauler and such, those are the service making money for the tracks. Passenger rail usually in the red because it is really hit and miss, you have enough ridership but you generally do not charge enough (Which is the reason why you have ridership)That is why Amtrak operates on tracks run by the commuter rail companies around New York. Their intercity service piggybacks on the tracks of Metro North and New Jersey or they just all share the cost in some kind of joint funding/operational standpoint.
At this point the best bet for the CA HSR is to get the tunnel built between Palmdale and the San Fernando Valley (in the tehachapi pass area) to allow for the private brightline west project to build out their project and connect to the section in the Central Valley for the sake of housing.
A lot of Americans feel public transportation is for the poor (and the poor have less resources to influence elections)
Which mean private-public partnership is the way to go for Railway, which would be a problem for HSR, because you cannot run HSR on freight line.
On the other hand, the purpose of Tunnel defeated the exact reason why they would need a HSR, you want the view, not the train when you hop on board, why I drove down 101 instead of Interstate (5??) is because I enjoy the view up in Santa Monica, not because I want to go thru the tunnel........
yet you raise no point other than "I am discussing now"I m discussing now