Yes, Sky, I am an Amtrak conductor. And while you may be livid, angry, disappointed, or upset when I point out to you that right on the face of the ticket is the statement that your membership card is required (and few discounts are granted on board; most discounts are honored only when your reservation is made 3 or more days in advance of travel), being removed from the train is at the conductor's discretion, for whatever reason. Your attitude plays a huge part in whether I pursue an issue, let it go, or something in between.
If you purchase a discounted ticket, please be prepared to show you are eligible for that discount. If you are unable to show you are eligible for a discount, please be prepared to purchase a new ticket and surrender the ticket you may have purchased inappropriately.
(In reality, I'm most likely to ask you to pay the difference between the discounted fare and whatever fare is standard. I do this with passengers whose grandmother, for example, purchased the ticket, on a senior discount, and the passenger appears to be under the age of 62...again, however, the demeanor, attitude, responses, and general cooperation of the passenger determines how I handle a situation.)
I would humbly suggest that you ensure your paperwork is in order before you travel, including proof of eligibility for discounted fares, to help prevent the potential for an unpleasant traveling experience.
I choose not to pursue or argue this topic any more.
Travel light!
~BJG