Basically, those same people who, fairly illegally, don’t want to serve gays can (and should) very legally be refused (nonesesential) service for being prejudiced against gays.
...please rewrite this sentence; your prose has completely obscured your point...
Sorry didn’t proof read before posting:)
The sentence you mentioned basically meant, if in a hypothetical world where these laws existed, someone were to refuse to serve gays, then they in turn could be refused service for being prejudiced against gays. Kind of a vicious cycle.