In ninth-grade civics class back in 1984, the teaching was that the USA was a “representative democracy”.
After that, I don’t know what high schools were teaching.
In the early 70’s, at least where I went to grade school, we were taught the U.S.A. is a Constitutional Republic (social studies class).
Plus at home....my parents made sure to drill it into us. My parents were/are very conservative Christians.
Even today, my Mother was yelling on the phone to me how sick she is of hearing people say we’re a democracy....LOL. She said people are just dumb and don’t even know what form of government we have and shouldn’t vote since they don’t know.