People interested in how 'hidden ideology' works in children's books, might like to look at the chapter on 'Captain Underpants' in "Boys in Children's Literature and Popular Culture: Masculinity, Abjection, and the Fictional Child" (New York: Routledge, 2007) by Annette Wannamaker.
Loosely speaking, we might say that there is 'explicit ideology' where authors appear to be stating what readers should believe. (Whether readers end up believing these things is another matter altogether, for the simple reason that there is no ideal 'reader' who follows meekly what appear to be the 'messages' or 'teachings' of a text.)
What's more, what might appear to be 'explicit' might possibly be 'ironic' and doing a bit of 'reverse psychology' on us. As with Jonathan Swift or books with 'unreliable narrators'.
Then people talk of 'implied' or 'implicit ideology'. This might be linked to the concept of the 'implied author'. This concept is that we never know what the author intended - and according to this theory, neither does the author. The only thing we know is the text. If we as readers or critics analyse and re-assemble the text, is it possible to see what this text 'implies'? If we think an author assembles a text then the 'person' doing that is the 'implied author'.
Then again, people talk of ideology that you or me or a lot of people or most people 'don't notice'. Indeed, some argue that the ideology you don't notice is the one that does the most work. So, if, let's say, I love a story and think I've spotted what it's got to say, but haven't 'noticed' the race hierarchy implied by the way in which different kinds of people are represented, then it's played along with my assumptions (if I have any) that race hierarchy is OK. To take this argument further, you might say that all texts have hidden ideologies - they may well be hidden from the author - and that that is the crucial part of how what Chomsky called 'manufacturing consent' works.
Some of this challenges 'ideological criticism' from the left as much as anyone. Looking back to criticism of children's books by someone like Bob Dixon, 'Catching Them Young' (1977), at the time it was a powerful challenge to many of the assumptions that many of us in the children's book world, parenting, editing, teaching etc made. So far so good. However, what he wrote rather assumed that there is a process that runs: "author writes ideology - reader believes it; leftwing critic resists it, most other people don't." He didn't ask the question, 'if I resist it, why can't or don't others?' He didn't ask the question, 'If a text appears to be stating an unpleasant view or ideology, why can't people respond to that by finding that repulsive?' He didn't make clear distinctions between the author, the implied author, the different 'positions' taken up by characters in texts who offer different perspectives on actions, which in turn offer different readers different ways to look at the book...(that's a lot of differences, but so be it!).
So, back to Annette Wannamaker, if any of this interests you, then the chapter in her book, makes for a very interesting and challenging read.