Trump has made a lot of noise about 'infrastructure' but hasn't provided many specifics other than wanting to eliminate other uses (like transit) of highway taxes. Hasn't said anything about increasing the gas tax, though, which is the only sustainable way to generate more highway money really - and a Republican Congress won't let an increase happen anyway.

So ... does the Amtrak subsidy come out of the highway money (if so, it's toast) or is is separate somehow? In either case, the end for Amtrak would come, I think, not from Trump but from Congress which has been trying to eliminate it for years. That'll happen again, and Trump will go along instead of fighting it. Though I do think he would be willing to entertain privatization schemes if something reasonable were offered, seeing it mainly as a service for rich tourists rather than as a transportation mode.