While I agree with you, I find it hard to argue against the view that politicians are elected for the views they held during their campaign. They may change their mind after being elected, but their constituents that voted for them will not all change their mind simultaneously. To the ones that don't change their mind, it does appear to be a betrayal of their principles. A rational politician would not want to gain that kind of reputation out of pure self-interest.
I would be much more inclined to continue voting for a politician who could explain their policy position as it changes in an open and sensible way. Politicians putting on a speech that sounds truthful and honest and like a discussion is happening between adults is so rare - it seems that very few people want that. I do though.
