For a political narrative to be a political narrative, people have to believe it. So how can political narratives belong to a different category than individual truths? Aren't political narratives just an expression of what we think is common to the political beliefs of many individuals? And how is science a "narrative"? The periodic table is not a narrative. It is a summary of certain laws of physics, which are mathematical expressions summarizing repeatedly observed phenomena.  McNight may be wrong in certain respects but he does not conflate all categories of knowledge with narratives. I have no doubt you are in good faith but post-modern thought allows people to believe what they want to believe without justifying their beliefs, McKnight is right about that.