Well. most fiscal conservatives are in favor of killing off the long distance trains that are a huge loss leader on Amtrak. The same folks are also arguing for cutting off the EAS subsidies (which the FAA Reauthorization seems to be doing).
There's definitely a need for some form of transportation across the upper plains, but let Montana, North Dakota, etc. fund it the way that Maine, Vermont, Michigan, Illinois, Missouri, North Carolina, California, Oregon and Washington have had to.
Amtrak hasn't covered its costs in 40 years... It's time to cut them loose the way Conrail was, and let the free market decide if they live or die, or if they're worth buying. Same thing with the USPS.
If rail needs to be funded as a public service, then leave it to the states to deal with. Get DC out of it.