Actually, the 20 60 20 rule means that 20% will conform, 20% will dissent, and 60% will be fence sitters.
It can be difficult to change his mind. I'm trying to compile a list of homophobic questions, but a good start might be to point him to a study published a couple years back in the Journal of Abnormal Psychology. Basically, some University of Georgia psychologists asked a bunch of heterosexual men about their feelings wrt homosexuality and exposed them to gay porn.
66% of nonhomophobic men showed no significant tumescence, compared to only 20% of homophobic men. Only 24% of nonhomophobic men showed obvious tumescence, compared to 54% of homophobic men.
As a rule, psychoanalytic theories explain homophobia as a type of repressed homosexuality. For once apparently psychoanalysis is worth something. | 
