dlh6213 is right- the points system is scaled in such a way that the vote of a member who has a higher point-count carries more weight than the vote of someone with a low rep.
I don't know exactly what that scaling is myself, but I do know that for the lower range of rep points there doesn't seem to be much of a difference in the weighting. That is, someone with 22 points isn't going to have much more "clout" than someone with 16 points or so.