Doonesbury by Garry Trudeau for July 20, 1971
Transcript:
Arnie: Mark, I think the reason you're having such a hard time relating to the guys is that you're so patronizing... Students have to stop feeling they are better than workers. Mark: Nonsense Arnie! I hold my fellow worker in great respect! Arnie: Would you want your sister to marry one? Mark: You must be joking.