I don't think you can separate what he says about his policies from the actual policies. They are part of a whole. "fluidity in meaning" is another way of saying they don't mean what they say. That doesn't mean they don't intend what they say to be taken literally. I don't buy the idea that people vote for candidates thinking "I know he/she was just making empty promises." The public may accept that politicians aren't always able to deliver on their promises, but not that the promises themselves were just some vague metaphorical allusion with no real intent behind them.