A record-low percentage of registered voters casting ballots in a primary election might have kept Mayor Mufi Hannemann from winning re-election outright. Instead, he will face City Councilwoman Ann Kobayashi in a November runoff, and his supporters should not be complacent.

Only 37 percent of Oahu's registered voters - and less than 35 percent statewide - voted in Saturday's election. Hannemann needed one vote more than 50 percent of those cast to win re-election. Instead, he received 49.4 percent, while Kobayashi received 30.16 percent and Pano Prevedouros, a University of Hawaii engineering professor, garnered 17.72 percent.

That means Hannemann received barely 1.5 percent more votes than the Kobayashi and Prevedouros totals combined - and their supporters might very well join forces on Nov. 4. Both Kobayashi and Prevedouros oppose Hannemann's rail transit project from Kapolei to Ala Moana, so opponents of the rail plan were motivated to vote.

That motivation might exist even more in the November election, which will include on the ballot a proposed City Charter amendment that would give the city transportation director the authority to go ahead with the “;steel-wheel-on-steel-rail transit system.”; Rejection of the amendment, while not legally derailing the plan, would make it difficult for the mayor to proceed with it.

Kobayashi, who favors a rubber-tire-on-concrete system, has been critical of the expense and adequacy of Hannemann's transit plan. She told the Star-Bulletin editorial board that the $4 billion line would take a commuter 26 stops and an hour of traveling time to get from Kapolei to downtown.

Actually, said Wayne Yoshioka, director of city transportation services, the 19-station rail system as planned would take 40 minutes to reach Ala Moana from Kapolei. Hannemann, who was less than aggressive in the weeks leading up to the primary, said he will hold Kobayashi accountable for “;every statement she made in the primary.”;

City Councilman-elect Duke Bainum, who narrowly lost to Hannemann in the 2004 mayoral race, asked his supporters before the primary to vote for anyone but Hannemann. Bainum's entry into the fray during the general-election campaign could increase interest in the race, which might actually help Hannemann, who needs a heavy voter turnout. Polls have shown that 60 percent of registered voters favor the rail transit and even a higher percentage support the mayor overall.

Those who stayed home on Saturday might be lured to the polling places by the presidential candidacy of Honolulu-born Barack Obama, the issue of whether to authorize a state Constitutional Convention and general election races between opponents who faced little if any opposition during the primary.