In any by-election, the battle between the two biggest candidates has traditionally been a David and Goliath story.

Though the young shepherd, David, slayed the 3m-tall Goliath with a pebble to the giant's temple from his catapault in this gripping good over evil story, the political reality is that when the odds are stacked against the underdog, they really show.

In the case of the Tenang by-election, it is PAS candidate Normala Sudirman who has to go uphill, if the opposition is to clinch victory.