Oh, the Lake Shore Limited was started as a state supported train by New York and Ohio, and indeed there were some serious prime protectors of it back then. Ohio dropped support but New York picked up the slack and kept it going until the prime protectors were able to twist Amtrak's arms and foist it off onto them. So yeah, just because a train has had a prime protector does not mean it will always need it. We will see about the Cardinal.
Remember, the prime protector initially of the Texas Eagle was the riders group until they managed to catch Kay Bailey Hutchinson's attention.And thence it evolved into a train that did not need any immediate prime protector beyond the active riders association. The best prime protector are activist riders.
BTW, if something serious like cancellation were thought of for the Silver Meteor or Silver Star, I know of a few that will rise up as prime protectors. At present we are just worrying about getting adequate food service back on the Star. We are waiting eagerly for Boardman's departure to address that one in right earnest. We need someone in command who can disown previous decisions without losing face. That is why it is bad to have the same CEO for more than a few years specially if he starts going off the deep end.