There seem to be two different ways to think about pornography and the danger it represents to society. The pro-censorship camp views pornography as a dire threat that society needs to be actively and aggressively protected from, the anti-censorship camp views some of it as a problem, but a problem which is confined to a relatively small fringe, well away from the experience of the bulk of the population.
I think the above graphic helps to conceptualize the differences. With the "Sphere" conceptualization, most of the population interacts with G-rated content and may occasionally take excursions away from the centre of the sphere into R- and X-rated content. Many are happy to stay in the centre of the sphere. There are some extremists who seek material that has been refused classification, but there is no inexorable force dragging the bulk of the population into the Refused Classification zone - on the contrary most of the the population is grounded by the gravity of common sense and shared moral values.
On the otherhand, in the "Vortex" conceptualization, the Refused Classification zone is a vortex or black hole into which society will inevitably and tragically be dragged unless there is active resistance.
The anti-censorship lobby thinks of the spherical world of content as being somewhat analogous to Mother Earth itself, dangerous in parts but mostly life-affirming, whereas the pro-censorship lobby is clearly committed to the more exotic vortex-shaped conception of cosmic and moral doom that one might expect to find in a bad sci-fi flick.
This, of course, is just a happy coincidence of the way I drew the analogy and not indicative of any selection bias whatsoever. Well, ok, maybe some.