The society is a complex system, politics is complex (you have to calculate what all those pesky voters say they want, think they want and actually want) and there are a lot of issues. No one in their right mind can be serious about trying to manipulate future elections through carefully crafting education for that purpose. Dictators do that, for sure. They can stay around long enough to benefit, but they rarely participate in fair elections.
Or where books are stricken from reading lists or curriculums for fear they make kids question authority [1] – where or Harry Potter's inclusion in school libraries is challenged for their focus on magic (often based on claims that the novels contain occult or Satanic subtexts) [2].
[0]: https://en.wikipedia.org/wiki/Creation_and_evolution_in_publ...
[1]: https://www.theguardian.com/books/2014/jun/10/cory-doctorow-...
[2]: https://web.archive.org/web/20071230201312/http://www.ala.or...