I'm assuming the candidates all have fairly similar beliefs about what is actually popular, even if they differ on what platform should win.
The winner is then determined by the difference between the candidates beliefs in what will be popular and the voting public's actual preferences. The winner inhabits a part of the landscape more sparsely populated by candidates than by voters.
It's an interesting property of a not very good voting system!
Looking at the Hugo award system, as the results have just come out: Hugo winners are based on preferential voting and should be good choices (from among the five nominees in each category). However Hugo nominees (with all eligible fiction for that year as candidates) behave more like first-past-the-post and may indicate differences between what authors and publishers think readers want and what readers actually want.
This year we see the amoeba of reader preference more elongated along a liberal/conservative axis than authors expected, perhaps.