Media usage of "unhinged rant"
Means that whatever the rant happens to be is true.
This is like the "wrap-up smear."
Just slime the truth in such a way that a reader/listener would not want to be associated with the smear-object.
Much like how child porn is always (alleged) to be on computers of those opposing the govt.
As soon as I see "unhinged rant," I know it is the honest truth.