Ideally you'd want something that makes your side feel it's desperately close, and that it needs every vote to win - and makes the other side feel it's really all over, and it isn't worth the bother of voting, because they are goingto walk it. And at the same the undecided need to think think that your candidate is on a roll, and that they want to vote for the winner.

The trouble is, that means getting a completely different message across to each set of people...