Regarding politics, we learned about it in American History. But it was nothing like "Well, the current President blah, blah, blah...:" or "The previous administration is blah, blah, blah..." It was only ever about the current 2-party system, early politics in The U.S., George Washington, Abraham Lincoln, etc. There was NEVER anyone shilling for one side or the other. It was completely open, honest, and non-partisan. So yes, teach politics in school. But teach it with an open mind and talk about both sides and how they differ. But do NOT talk about why one side is better than the other.
Unfortunately, that's where the message gets lost. Teachers are influential people. They know this. So they use that influence to tell kids in their classes why one person is bad and that they should be for the other. And they push their own agenda and try to keep the parents unaware of their "teachings". That's why if I EVER had kids (not likely, especially at my age now), they'd be home-schooled.
Yes, I vote a certain way. My entire family votes a certain way. But we always talk to the younger generation about politics in an open manner and let them make their own decisions. Just as it was when my younger niece turned 18 a few years ago. My sister told her about both parties, both candidates, and let her make up her own mind.