Doonesbury by Garry Trudeau for September 10, 1977
Transcript:
Voice: Leon, I wonder if you'd have any comment on the likelihood of a Koreagate cover-up... Leon Jaworski: Well, Ji, as might be expected, there have already been instances where co-operation has not been forthcoming and where active evasion has occurred. As with Watergate, we suspect that many will suffer more from their attempts to withold facts than from the facts themselves! ... Yes, Frank. Voice: Yeah, Leon, who's your assistant over there with lint on her shirt? Joanie: AAIEE!
Correct, Koreagate was the first where it was used as a suffix.