From an environmental point of view replacing planes with trains can help (look at the CO2 emissions of a TGV compared to a 707-300 (the JT4A powered model not the JT3D powered model), I know that's a bit of an extreme comparison) although in terms of travel time high speed trains can only beat planes for journeys of less than 1000 km (and that requires that people not have to go through security or check baggage, etc like at airports) although with the slower high speed rail currently used in the US the distance would probably be a bit less but even so nearby capitals could benefit from high speed lines or tilt trains on normal but well built track (with the bombardier Jettrain you could even get away with not electrifying it, although consider that the French had a reason for switching the TGV to electric (the prototype had a gas turbine)). As I understand it, Amtrak was set up because the private companies didn't want to run intercity passenger trains they were required to run (which weren't very profitable) so the government took them over. Passenger rail typically doesn't make much profit anyway (freight is where the money is) and even when passenger rail is privatised usually the government is paying a subsidy to the company that runs the franchise (and varying the subsidy based on performance even if they call it a fine), in the few instances in which a passenger rail system makes more in ticket revenue than operations cost it still couldn't repay capital and infrastructure maintenance costs. You could of course raise prices to pay for it but then you also reduce demand, not to mention that the prices are set so as to be affordable to people who can't use a car. The proposal for shut down of rail services probably won't go over too well with the public anyway (at least if it actually looks like it'll happen), public outrage has often caused a lot of such proposals to end up watered down to the point at which they only close a few of the lesser used lines to passenger services.