I've got a couple of people I can call for advice, and that helps. But when the promotion list gets drawn up in a room I'm not in, I don't have anyone in there fighting for me. My mentors will grab coffee and tell me what they think; getting someone to actually put their name behind mine is a different thing entirely.
More people experience this than they realize.
You have people who advise you but nobody who champions you when it counts.
If this sounds familiar, the Library can help you find the bigger picture.