Tinker was one of five students who in 1965 wore a black armband to school to protest the Vietnam War. She was suspended by school authorities. Four years later, the Supreme Court ruled by a 7 to 2 vote that the school authority was wrong to punish her action.
The re-enactment was part of a project to teach school children about the rule of law. 6 min, transcript available.
For an update on student free speech, see this post.