I see what you mean.
My only contact with these books has been through your post, I assumed they were just satire disguised as children's books. The celebrity charicatures and leering Democrat donkey wearing a press card in his hat seemed aimed more at grownups, I don't think most kids are that sophisticated. However, from your description, the liberal lemonade stand holdup definitely clinches it. (Why is the kid's lemonade stand always held up as the conservative business model anyway?) Lemonade stands don't employ workers, lobby governments, and they don't compete against other lemonade stands.
How do these comments relate to your Democratic example? At least, the artwork in that appears gentler in style.