I would second this recommendation. The more contact people have with the congressional representatives (house and senate) and the more they talk about the need to support Amtrak helps to get the attention of the people who vote for funding + you may also be able to eat in the congressional cafeteria - out tax dollars at work!
Personal visit > letter or fax > telephone call > email is the general rule for "how much does your input weigh with your congresscritter". So given the opportunity for a personal visit, take it! (And of course, "personal visit" probably does mean "meeting with a recent poli-sci graduate from their state serving in a four-month internship", which may disappoint you if you were expecting to actually meet your elected officials. But the influence it will have on your elected official is basically the same.)
yes it is funny how everyone thinks they'll actually talk to their congress critters but over the years I have actually met in person my own, at least once we were the only two on the elevator and got the longest meeting I ever had with the real guy. however every one of them has a "Transportation issues" aide and these are the people who know his basic feelings and sum up what you are trying to tell them. Most are pretty decent folk.
one mistake first timers tend to make is "too much information" keep it simple,, keep it short, and stay on point. don't talk down to them but let them know,
1. I ride Amtrak, (especially if you use a station in their district)
2. I think Amtrak is important
3. please support Amtrak funding and support.
add your own flowery speech but unless they ask questions and they often will, 5 minutes is a lot of time, and be prepared to wait if you don't have an appointment, and often if you do have an appointement, that highway lobbiest is there bending their ear too.
But JQ public is often heard much louder than the folks that are paid to be there, because they know you are in their district and vote for them or the other guy and because you are taking your time on your own nickle to be there, you could be in the Air and Space museum having a much better time.
ALSO be warned that the cops in Union station have been hassling the folks taking pictures of trains... and they are being hassled back by ACLU and a whole bunch of others. I have a letter from Amtrak saying it is ok, will see the next time I'm there in about 2 weeks
good luck and enjoy your stopover. be sure and take a ride on metro too.
Bob