Firm, clear examples of the slippery slope argument are very helpful in helping people change their minds.

Observing our society going from "gay shouldn't be in the open" to "gay is legal in cali" to "yaaayy gays!!" to "im going to literally mutilate my genitals" was a pretty big deal for me.

Sorry, I know, too little too late, but better late than never I always say.