Republican U.S. Rep. Charles Djou and Democrat Colleen Hanabusa are battling over Hawaii’s 1st Congressional District, but there’s a third person at work in the Nov. 2 general election: Ed Case.

Case, a Democrat, is not on the ballot. But as the third top vote-getter in May’s 14-candidate special election, he and the 47,400 voters who chose him last spring are key players in the current contest between Djou and Hanabusa.

"She has to get two of my voters for every person that votes for Djou. That’s how she wins," Case said in an interview last week.

Djou, a Honolulu city councilman at the time, captured 67,600 votes, or 39.4 percent, in May to win a seat that had been in Democratic hands for nearly 20 years. Hanabusa, the state Senate president, garnered 52,800 votes, or 30.8 percent.

Case, a Honolulu lawyer who represented Hawaii’s 2nd Congressional District from late 2002 to 2006 before stepping down to unsuccessfully run for U.S. Senate, attracted 27.6 percent.

Djou acknowledges that to win, he must gain a significant share of moderate Democratic and independent voters who were attracted to Case’s mix of social liberalism and fiscal centrism.

"I think its important to reach out to independent and moderate voters," in part by door-to-door canvassing in neighborhoods where Case did well last spring, Djou said in an interview. "They’re the ones who are going to decide this election."

Similarly, Hanabusa needs to attract a larger share of Case’s voters or convince Democrats who passed on the special election to vote for her next month.

"We are going after the Case vote," Hanabusa said in an interview. "We are reaching out in terms of our calling … as well as where we canvas."

Still, Hanabusa isn’t overtly appealing to Case’s voters.

Case endorsed Hanabusa in late May in a speech at the state Democratic Party convention, an act that both Democrats said was crucial. But her strategists have not made use of him in her television ads or news conferences.

He continues to strongly back Hanabusa, though he said neither of the candidates seems to have the qualities to attract many of the voters who backed him.

"Neither Charles nor Colleen are independent by instinct," Case added. "They are in fact creatures of their parties."

Hanabusa and Case met in June to discuss how she could appeal to his supporters, but some Case allies say she still hasn’t done enough to capture their support.

Hanabusa will easily win over Case voters who are rock-solid Democrats, but she faces difficulty with those who favor ideological balance in Hawaii’s congressional delegation and independence from its Democratic establishment, said Bernie Bays, a senior partner at a Honolulu law firm and a major Case contributor.

Bays said those voters were key in the Sept. 18 primary election, when Peter Carlisle and Neil Abercrombie won their respective contests for Honolulu mayor and the Democratic gubernatorial nomination over rivals perceived as too close to the establishment.

"That wouldn’t bode well for (Hanabusa’s) ability to gain the support of voters who are seeking some independence from the Democratic power structure," Bays added.

He said he has not decided whether he will vote for Hanabusa or Djou.

Hanabusa insists her political history demonstrates more independence than she is given credit for, even if influential U.S. Sen. Daniel Inouye and labor unions endorsed her last spring.

Public employee unions have refused to back her in previous campaigns, and as the state Senate’s leader, she has worked with all sides, she said.

"If (voters) don’t recognize that, there’s no way we’re going to be able to convince them of the fact that I have always been independent" and have shepherded legislation that has "caused change," she said.

Djou also is attempting to coax Case voters to his side by highlighting fiscal responsibility and government accountability, the candidate said in an interview.

"My campaign is focused on one very, very simple question: Are you satisfied with Congress? Are you satisfied with the status quo?" said Djou, who also met with Case after the May election. "I think that’s a message that is resonating well with Case’s voters."

If nothing else, Djou has at least trumped Hanabusa in family ties — he said his wife is a step-cousin to Case’s spouse.