Sen. Brian Schatz speaks at a press conference in May. (Oskar Garcia/AP)

Daniel K. Inouye, the most revered and powerful figure in Hawaii political history, had a deathbed wish: that Gov. Neil Abercrombie (D) would appoint his protegee, Rep. Colleen Hanabusa, to replace him in the Senate. But Abercrombie upended this island state’s political order by tapping the younger Brian Schatz, then the lieutenant governor.

Now, a year after Inouye’s death, the former senator’s ghost lingers large over a bitter feud that is dividing Democrats along ethnic and generational lines here in President Obama’s birthplace. With the outspoken support of Inouye’s widow, Hanabusa is giving up her House seat to challenge Schatz in the 2014 primary.

Unlike in Republican primaries across the mainland, this is not a clash over ideology. Although Schatz is more progressive than Hanabusa on some issues, both candidates are considered solid lawmakers and viewed as safe bets in this overwhelmingly blue state to keep the Senate seat in Democratic hands.

Rather, the divide is personal, and it’s unique, like the state where it’s playing out. In Hanabusa’s candidacy, what remains of Inouye’s mostly Japanese American political machine is fighting for supremacy against a younger and whiter progressive wing that is trying to become Hawaii’s new ruling class.

Randy Perreira symbolizes the evolution. In a state where Democratic politics is powered by organized labor, Perreira, as head of the Hawaii Government Employees Association, the state’s largest union, was a trusted Inouye ally. But after Inouye’s passing, Perreira and his workers have lined up behind Schatz.

Rep. Colleen Hanabusa poses for photos with former senator Daniel Akaka during a rally for her 2014 campaign in July. (Jamm Aquino/Honolulu Star-Advertiser)

“God bless him, but all of us are moving on,” Perreira said of Inouye. “While we will forever be respectful and grateful for all that he did, we all knew the day would come that we would be without his services. We’re just charting a new path.”

A new path is what Abercrombie had in mind when he picked Schatz a year ago. In an interview in his top-floor office at the State Capitol, Abercrombie said, “It had very little to do with Brian and Colleen themselves as people. It had everything to do with the future and the past.”

Abercrombie said he disagreed with Inouye’s wishes, adding that he didn’t want to “get into a discussion about letters and deathbed notices.” The governor said he thought Hanabusa, now 62, was too old to build enough seniority in the Senate to continue Inouye’s legacy of steering an outsize allowance of federal money to Hawaii.

Noting that Inouye entered the Senate in 1963 at age 38, Abercrombie said: “Brian Schatz is 41. Colleen isn’t. She’s in her 60s.”

Hanabusa said Abercrombie’s focus on her age is “rather offensive.” Over lunch at Zippy’s, a local casual-dining chain, Hanabusa sounded angry and at times bitter that Abercrombie passed her over for Schatz, whose résumé in state government she believes does not stack up to hers.

“By saying that he’s putting somebody in so they can get seniority, it’s like saying to the voters, ‘You’re not relevant. Here’s somebody who’s going to be there forever,’ ” Hanabusa said. “No one — no one — should feel that level of entitlement.”

Hanabusa spoke of Inouye in complete reverence, calling her mentor simply “Senator.” She recalled Inouye recruiting her, then the president of the state Senate, to run for Congress in 2010.

“Senator told me then, ‘I think that you should consider this position because I’ve watched a lot of people and I believe that you’re someone who can really succeed in Washington and I’d like to see someone like you eventually take my place,’ ” Hanabusa said. “That was when it all started.”

The Schatz-Hanabusa race carries echoes of the 2008 Democratic presidential contest between Obama and Hillary Rodham Clinton. Schatz led an early “draft Obama” movement here and became the face of Obama’s campaign in the Hawaii caucuses.

Meanwhile, Hanabusa, at Inouye’s urging, helped lead Clinton’s campaign here. “When Senator came to see me . . . he said, ‘We may come off looking a bit lolo because Barack Obama is from here, but let’s do it,’ ” Hanabusa recalled, using the Hawaiian word for crazy.

Obama beat Clinton in the caucuses, 76 percent to 24 percent. Obama has not endorsed either candidate in the Senate primary.

Schatz has reported raising $2.7 million, compared with Hanabusa’s $1.2 million, as of Sept. 30 — partly because of help from party leaders and the Democratic Senatorial Campaign Committee, which backs all incumbents.

Precise polling is notoriously difficult in Hawaii, but early surveys suggest that the Schatz-Hanabusa race is a tossup.

Hanabusa, who is Japanese American, may seem to have a leg up on Schatz, who is white, considering voters of Asian descent far outnumber whites. But Schatz and his campaign advisers said the state’s historical pattern of ethnic-bloc voting is evolving quickly.

“It’s not a paint-by-numbers kind of a thing,” Schatz said. “It’s a matter of representing Hawaii’s point of view, and that is diverse — we are a patchwork and we intermarry and our kids play together.”

The Democratic infighting is bleeding into the 2014 governor’s race, where Abercrombie’s low approval ratings, particularly among Japanese American and native Hawaiian voters, make the white incumbent vulnerable. Some Democrats, including former governor Ben Cayetano, are lining up behind a primary challenger, state Sen. David Y. Ige, an Asian American who chairs the Ways and Means Committee. But Ige has raised little money and has a low profile statewide.

Republicans hope to take advantage of a divisive Democratic Senate primary, scheduled for Aug. 9. Former congressman Charles Djou said in an interview that he is among those Republicans considering a run and that he sees an opportunity to campaign from the ideological center.

“Brian and Colleen seem to be running a contest as to who can be the left-most extreme liberal candidate,” Djou said.

Schatz is running as proudly progressive. His campaign notes that he leans to the left on environmental policies; that he was an early supporter of same-sex marriage, which is now legal here; and that, with the looming retirement of Sen. Tom Harkin (D-Iowa), he is assuming the liberal mantle on Social Security.

He also touts his potential to attain Inouye-level seniority, quipping that he told his wife that he won’t retire until he’s 85 — that would be seven six-year Senate terms — if the voters allow it.

Hanabusa said she is most focused on protecting the military’s investments in Hawaii and on the U.S. foreign policy pivot to the Asia-Pacific region, which could be an economic boon for Honolulu — although these have been priorities for Schatz as well.

Hanabusa has the backing of several Democratic leaders who had been Inouye allies, and she is promoting the endorsement of Irene Hirano Inouye, the senator’s widow, who has been attending events and helping Hanabusa raise money nationwide.

“For him, serving the people of Hawaii was always first and foremost,” Hirano Inouye said of her husband in a telephone interview from California. “I see Colleen as having the same qualities.”

Many of Inouye’s former Senate colleagues are siding with Schatz, including Majority Leader Harry M. Reid (D-Nev.) and Sens. Charles E. Schumer (D-N.Y.) and Richard J. Durbin (D-Ill.).

Former New York mayor Michael R. Bloomberg (I) will headline a fundraiser for Schatz in Hono­lulu on Thursday, while former vice president Al Gore (D) has endorsed Schatz, citing his record on clean-energy development.

Schatz is playing up these out-of-state friendships. A recreational surfer, he said he has offered to teach all 99 of his Senate colleagues how to ride waves.

“I think it accrues to Hawaii’s benefit that I have friends in Harry Reid and Chuck Schumer and Dick Durbin,” Schatz said. “We’re already geographically isolated, so it’s really critical that we don’t become politically isolated.”

Reid Wilson in Washington contributed to this report.