I've been looking at the social power of narratives for a while, and you seen to get the idea over quite well. Here is a Scientific American Mind article which supports the power of storytelling: The Secrets of Storytelling: Why we Love a Good Yarn.
Politically a good narrative trumps a lot of powerful facts because that is the way the human mind works. That's true even when the story being told is blatantly fiction.
Since one of the major focuses of a liberal education is to overcome the desire for a good story when the facts demonstrate that it is false, we liberals are trained to downgrade the importance of narrative. But the major religions are all transmitted through narratives. So is the American conservative movement - certainly it has been since Reagan started telling the Welfare Queen story.
Another example is Ayn Rand's book "The Fountainhead" which is the narrative soul of Libertarianism in America today. Fact? Not a bit, but any facts that are presented to demonstrate its falsity literally bounce off of the narrative power of that book. Try arguing with a committed libertarian and you will see that there is no rationality in their position.
Tribalism is passed on through narrative, not through any form of science or reliable truth. For a modern example of such tribalism Michael Wolraich points out (in his TPM Cafe essay How a Story Seduced the Right Wing) that the conservative movement is a tribal group held together through a series of narratives.
When I started trying to understand the nature of narrative I was referred to an essay "Notes on the Origins and Life of Narrative" in Reynolds Price's excellent book "A Palpable God." It is the best discussion of narrative I have ever found. The rest of the book is Price's translations of various books of the Old Testament which he presented as outstanding example of narratives. The desert religions are based on the tribalism carried in those stories. I found the same narrative power in an excellent book called "The Teachings of Buddha" by Paul Carus. Again the stories were told and refined by storytellers (because of their narrative power) for centuries before ever being written down.
These days many of the best narratives in America are crafted by advertisers and PR people. The conservatives have adopted narratives as ways of communicating and attracting others to join their tribe. Rush Limbaugh crafts narratives and tries them out on his audience, then modifies them to improve the power to get people to do what he wants.
It's going to be difficult for liberals to fight the political battle based on mere facts and science. The human mind prefers narratives to determine how to behave - or to vote.
[I haven't read it yet, but Michale Wolraich recently published a book on this subject entitled Blowing Smoke: Why the Right Keeps Serving Up Whack-Job Fantasies about the Plot to Euthanize Grandma, Outlaw Christmas, and Turn Junior into a Raging Homosexual.]