The attack has to think it is going to bother the politician. It may fail to, but it has to believe it will, else how is it going to score any political points? “Hey look, you live in BC!” wouldn’t go anywhere. All you are going to get is “Yeah, and?” – both from the ‘assailed’ and those you are trying to score points with. It has to prey on what someone think’s is another’s insecurity to have any use.