Last night, three candidates for mayor of Honolulu got together for a live televised debate sponsored by this newspaper and KGMB9.

It was one of the few times the three — Mayor Mufi Hannemann, City Council member Ann Kobayashi and University of Hawai'i professor Panos Prevedouros — are likely to appear together in any kind of structured format during this campaign.

Hannemann, the front-runner in name recognition and money and by mere fact that he is the incumbent, has little to gain and more than a little to lose by spending much time on stage with the other two.

He could take an above-it-all approach and ignore his challengers altogether. You can bet some of his advisers are suggesting this course. But people would notice this and take offense. And then, if one or more of the others managed to sandbag the incumbent into some kind of appearance, it would take on out-of-proportion relevance.

That happened to former Mayor Eileen Anderson, who managed to unseat veteran Mayor Frank Fasi in 1980 but then lost in a rematch in 1984. One of the factors in that loss was Anderson's refusal to debate or appear with the scrappy Fasi, only to agree to a single appearance at the last minute.

The event took on oversized importance, with live television coverage and huge public attention. Fasi did well in that debate and because it was the only time most voters had a chance to see the two side by side, his performance was magnified.

So Hannemann has a delicate task ahead. He must maintain his aura of front-runner and avoid giving his underfunded but determined challengers more credibility. At the same time, voters expect their candidates to be answerable and available.

In the case of this election, there is practically only one topic: mass transit.

Kobayashi likes mass transit, but is doubtful about Hannemann's tried-and-true steel-on-steel rail technology. Prevedouros, an engineer, thinks the rail transit project is a loser and would instead construct elevated guideways that could handle buses and car-pool lanes.

In most elections, fundamental demographics are the final deciding factor. People tend to vote the way they do because of their age, their education, their ethnicity and most of all, their income.

Any smart campaign can analyze those demographic factors and come up with a winning formula given enough effort, time and money. But if a campaign allows the demographics to get overrun by a particular issue — perhaps a simple refusal to debate often enough or a one-off subject like mass transit — then all the money and planning are for nothing.

That's the nightmare that the Hannemann campaign has to deal with.

Jerry Burris' column appears Wednesdays. See his blog at http://akamaipolitics.honadvblogs.com. Reach him at jrryburris@yahoo.com.

Jerry Burris' column appears Wednesdays in this space. See his blog at blogs.honoluluadvertiser.com/akamaipolitics. Reach him at jrryburris@yahoo.com.