Most candidates change their positions on various issues before or during a campaign to reflect what they believe their constituency wants. One could give them the benefit of the doubt, and assume they do this because they want to truly represent the will of the people. Or one could cynically assume they do it because they have no true convictions and will say whatever they think will get them elected.
Personally, I would prefer a candidate to 1) have convictions, and 2) be forthright about them. That way, even if you don’t agree with him on every issue, at least you know what you’re voting for. Otherwise, your vote is just a toss of the dice.
When a candidate changes his positions based on perceived public opinion, you can’t tell what to expect if he’s elected. Public opinion is fickle and easily swayed. I just can’t vote for someone whose stand on an issue is “Whatever way the wind blows.” Politicians who believe public opinion polls are gullible, at best, and not to be trusted with the fate of the nation.
A candidate who has his own convictions might change his mind on a particular issue if he encounters sufficient evidence to convince him that another position is more consistent with his convictions. But, if you know what his core convictions are, and they’re aligned with your own, as long as he’s competent, you can vote for him with confidence that, if elected, he’ll act in your best interests.
I want to vote for a candidate who represents me. I can only do that if I know what he truly believes in, and can trust that he’ll always act according to his convictions. When every individual votes for the politicians who best represent them, we have a truly representative government. We don’t need each politician to try to represent everybody. We need politicians we can trust. (Or is that an oxymoron?)