As a teacher I’ll say that political ideologies very much do belong in the classroom. How else can you expect a child to learn how to be a part of society and to care for people beyond their own self-interest?
Teaching “political ideology” isn’t telling a class of kids, “you should all be socialists,” it’s giving them a foundation upon which they can build their individual morality.
What is school if not a place to learn from the successes and failures of peoples past?