Girls were not allowed to wear slacks in my school when I was growing up. WE CHANGED THAT, WHILE I WAS THERE. I personally didn't do that much, but LOTS of kids were aware, they made their parents aware, they fought, and they won, because wearing skirts in the snow is FUCKING STUPID. And it was the kids who organized the change, not adults.
The gum thing also was largely put to an end. Gum itself remained forbidden because of the cleanup mess (i.e. the majority of kids, after having to clean up some old gum, concluded that it wasn't reasonable to allow it in school), but other food became acceptable. Unfortunately, the nature of kids resulted in this 'other food' largely being candy.
Gum, cigarettes, drugs - you'd get in trouble, but you wouldn't get sent home for anything less than violence or gross misbehavior. And as long as your stuff, whatever it was, was in your pockets, it was NO ONE's business, because the right-wingers thought so too. I suppose if someone showed up with a syringe the police might get called, but it didn't happen.
Teenagers couldn't vote, but they could and did work for, or against, local political candidates. Not all of them, but those who were either interested or saw their future in the local business community. They could also get a lot done through Grange, 4H, the Chamber of Commerce, the still-active fraternal organizations (Lions, Eagles, Odd Fellows, Elk, Rotary, and more), where young people were introduced to the local political power structure.
I knew kids who were aware and kids who were unaware, but I knew none like the many I meet in college now who will actively, intelligently argue AGAINST human rights. They've been taught that it's cool to disrupt and overthrow traditions, because they're all oppressive. And human rights is an OLD tradition, from the humanist tradition, which is the 'enemy' to postmodern theory, even more so than fascism, which is the normal preferred state of things.