Flip-flopping on Issues

When and when it is not okay.

Whenever I hear a pundit accuse a politician of flip-flopping I laugh. It is funny to me that politicians are not allowed to change their minds on issues. Why can't these people have a change of heart? It is okay for anyone to change their mind on an issue if they have received new information. But, it is not okay for candidates to change their mind on an issue to pander for votes.