Not so much as Senator Sanders (I'm a Hillary supporter, but believe that the Republic would survive if Sanders ultimately wins the primaries) as forward-thinking progressives and Democrats taking control of the House of Representatives and the US Senate away from the right-wing Republican reactionaries who currently control it. It's these Republicans who control the purse strings and keep the US intercity passenger rail network as flimsy and under-funded as it is.
I would like to see new Amtrak Chicago-Florida trains instituted as well as the Sunset again extended from New Orleans to Orlando again. As a Texan, I would like to see the return of the Lone Star from Chicago to Houston and either the pre-Amtrak (Burlington Route) Texas Zephyr running from Houston to Denver or the (ex-Rock Island) Twin Star Rocket running from Houston to Minneapolis/St. Paul. Unfortunately, getting such trains back again means making clean sweeps of such reactionaries as Ted Cruz, Don Inhofe, Ron Johnson, Tom Cotton, and other stunted-visionaries in the Senate and also their counterparts in the House.
Off-topic, I think progressives' standing would improve if more of our voters stopped seeing our President as a king or figurehead and more like a football quarterback. Quarterbacks might be great and deserve glory, but it's the linemen and receivers together with the quarterback that scores touchdowns.