You're not supposed to know about them openly, that's under-the-hood stuff. It's just the internal way of representing people's loyalties and interests, not an actual club that you can see who's a member of. (If you saw the trailer video mention things like "the traditionalists" trying to kill you? Stuff like that. You might or might not work out that some Electors lose approval when you violate traditions but you can't get a list of that sort of thing.)