Nixon and Kennedy did debate in 1960. It was the famed debate that those who listened to it on radio thought Nixon won and those who saw it on TV thought Kennedy won because of Nixon’s 5 o’clock shadow and sweating profusely. I was 17 at the time and watched it on TV.
Yes, I know they debated. I was thinking of Nixon’s subsequent successful runs. I do not remember Nixon debating either Humphrey or McGovern.
I was living in West Berlin when Nixon ran against Humphrey, so perhaps I didn’t see it. I am pretty sure he didn’t debate McGovern.