What counts as a fact, what counts as in debate, and what's outside

David Roberts at Grist had a good post last week on what the traditional media treats as fact, what's considered within debate ("he said, he said"), and what's considered outside the realm of possibility. We have these categories, but how they're used doesn't actually correspond with what we know about reality.

Many things stay in one category for a long time, rightly or wrongly; others have moved across categories (climate change, for example, has always been an interesting case to watch). The right, Roberts notes, is terribly good at pushing things across the categories in the way it wants.