My mother was a senior in high school in 1970. She was a straight arrow kind of kid...not doing drugs, not drinking, not causing trouble. She did her homework and went to football games. She wasn't completely "my country right or wrong" but she sure wasn't out protesting the war.
Kent State changed her views completely. After what happened there, she realized that she could just as easily have been a kid walking through a protest and been in the same position. Though Kent State may have been the end of the protest movement for many, it was what got my mother started.