I think a lot of that is just that if the person in question clearly does just say whatever they think people want to hear, then a dramatic change in position a

I think a lot of that is just that if the person in question clearly does just say whatever they think people want to hear, then a dramatic change in position appears more likely to just be more of the same. Romney suddenly being against "obamacare" is a good example. It doesn't appear that he changed his mind because of new information, since he still claims his version of the same thing is great, but Obama's is terrible.