This is classic big government nonsense.
The only place where they might be a demand for this sort of thing is the northeast - where it is completely unaffordable.
You could probably build it in Texas, but no one will use it here.
They already have the Acela train that runs from Portland to Boston to Providence to NYC to Philly to Baltimore and finally to DC.
The only people that ride it are people who live in the city where it is convienent to get to the station.
The only time I ever considered taking it was into NYC because it brings you into Penn Station(under Madison Square Garden) in midtown Mahattan. The main reason there is it is SO EXPENSIVE to park your car in NYC($45+ a day).