Can stories change the world?

I've been thinking a lot recently about how stories can effect positive change. I remember working in a job where employees were stuck in negative storytelling patterns. It was like we were all trapped in the same story : 'it's rubbish, no-one ever listens to us, what's the point? etc. etc.' I attended a storytelling conference at around the same time and started to wonder whether workshops with staff to encrouage them to start to tell different stories might somehow help the organisation break out of this negative cycle. I didn't follow my idea through, but the connection between stories and positive change has been following me around ever since. My logic is, if we can tell a different story, then that can open up a space for a different narrative to happen. The story itself won't change things, but it can create the space and the possibility for change to happen.
I've been thinking about this again in the run up to the US election. When commentators questioned whether the US would ever elect a black president, I couldn't help thinking, well, the story has already been told; we have all read novels and watched films where there is a black US president. That space has been opened up by fiction, and perhaps now is the point reality can step in.
I'm not suggesting that the films casting black actors as the US president are responsible for Obama's victory, but I do wonder if they played a role, if the world came to this election having already seen a black man in the white house, and decided to step into the space made by those stories.