Lt. Gov. Josh Green has attracted the major political endorsement so far in the three-way race for the Democratic Party primary election for governor, adding to Green’s already dominant approval ratings and fundraising haul.

Green has been endorsed by the Hawaii Government Employees Association, Hawaii’s largest public workers union with nearly 37,000 members; and by unions representing teachers, firefighters, electrical workers, brick layers, and plumbers and pipefitters. In addition, he has attracted financial support from health care organizations and individual doctors.

The union representing carpenters has yet to make a gubernatorial endorsement.

Endorsements — especially from labor union leaders — send a message during political campaigns that candidates generally align with their members’ interests and values, said Ngoc Phan, an assistant professor of political science at Hawaii Pacific University.

But candidates such as Green should not assume they’ll win every member’s vote or take anything for granted in the months leading up to the Aug. 13 primary and Nov. 8 general elections.

“Just because you are endorsed right now, we are far from November,” Phan said. “There’s a lot of things that union members and organized interests will be thinking about between now and then.”

In the 2020 race to regain his job as Honolulu mayor, Mufi Hannemann received endorsements from the Hawaii Fire Fighters Association Local 1643 and Hawaii Teamsters and Allied Workers Local 996, which represents city bus and HandiVan drivers, among others — but lost the election.

In the same mayoral race, former Congresswoman Colleen Hanabusa was endorsed by the International Longshore and Warehouse Union Local 142, Hawaii State Teachers Association and the Laborers’ International Union of North America Local 368 — and also lost.

But endorsements matter in Hawaii, particularly from unions that are skilled in messaging and mobilizing members to turn out to sign-wave — especially across the islands during the statewide gubernatorial and lieutenant governor’s races, said Colin Moore, director of the University of Hawaii’s Public Policy Center.

In the crowded five-way race for lieutenant governor, House Finance Chairwoman Sylvia Luke (D, Punchbowl-­Pauoa-Nuuanu), has been endorsed by HGEA, HSTA, University of Hawaii Professional Assembly, Masons Local 630 and Plumbers &Fitters UA Local 675.

“She has all of the big ones,” Moore said.

In a statewide race, “unions can fire out her name,” he said. “For someone like her who is an insider with little name recognition, it will matter. But endorsements alone are not going to be decisive. Every vote counts.”

In a statement to the Honolulu Star-Advertiser, Luke said: “The working people of Hawaii’s unions contribute heavily to our state’s economic and social successes. … To know that these groups are aligned with my vision for the state is both humbling and encouraging.”

Such overwhelming support for Green underscores his current status “that he is by far and away the front runner,” which could lead to even more donations and endorsements, Moore said.

“It is very humbling to be supported by such a diverse and broad base of Hawaii’s workers, from teachers to government employees to firefighters and doctors to those who fix and build our homes,” Green told the Star-Advertiser in a statement. “I feel honored to have so much support.”

Support for particular candidates can also backfire on the unions themselves.

Neil Abercrombie was considered a friend to labor before he was elected governor in 2010, then pushed a proposal that cut teachers’ pay and benefits that led to a lawsuit. And not even 18 months in office, Abercrombie was caught on video at a public meeting on Maui having a heated discussion with a nurse during a contract dispute.

Abercrombie served one term.

Abercrombie’s disputes with teachers and nurses showed what can happen when governing runs against the interests of unions, Moore said.

“You certainly don’t want to run against the people who endorse you,” he said.

Unions and organizations that endorse a winning candidate expect that their issues will be heard, Moore said.

“You’ll have a seat at the table at a minimum and probably consideration for whatever issue you’re concerned with,” he said.

Gubernatorial candidate Vicky Cayetano, a business entrepreneur and Hawaii’s former first lady, said: “The upside of not getting any endorsements is that you are not encumbered with obligations. Any candidate who gets an endorsement is more aware, obviously that the endorsement is given with an understanding of like-mindedness, shall we say. There is an assumption made by the unions.”

Cayetano, who said she has been creating “jobs for the last 34 years,” insisted that she is focused on “taking my case directly to voters, including the members of those unions.”

In a statement to the Star-Advertiser, former Mayor Kirk Caldwell said that he was “disappointed” in his lack of endorsements so far in the governor’s race.

“My record clearly shows that I’ve supported labor and issues that affect working people throughout my life,” Caldwell said. “I’ve also appreciated union endorsements in the past, for which I worked hard to get, and rightly so. I believe endorsements should be earned.

“In this race, I am disappointed that the union endorsements are going to others, but that doesn’t change my desire to always help the working people, and to honor and respect the history of labor in Hawaii. This time around I am not the front-runner. However, I will continue to value my union relationships, I will never take them for granted, and that’s just who I am.

“I’m a history buff, so I know that this state was built on the backs of working people. An endorsement is certainly valuable, but it’s the relationship with the organization’s members and their well-being that will forever be the most important thing for me.”

Former Council Chairman Ikaika Anderson, who is running for lieutenant governor, is still interviewing with organizations and unions for potential endorsements but has received none so far.

But he does have the support of Abercrombie, current Council Chairman Tommy Waters, former Kauai Mayor Bernard Carvalho and other former neighbor-island elected officials.

His support comes from “genuine friendships” and a reputation for helping individual union members and their interests, Anderson said.

“Endorsements are always nice,” he said. “Endorsements are always helpful to have, but it’s also important to reach out to the rank-and-file members. I can walk onto any construction site in the state and be recognized by rank-and-file laborers because I’ve always let them know that I care about them and their issues.”

The other Democratic candidates for lieutenant governor are:

>> Former state Sen. Jill Tokuda, who said in a statement:

“I understand why union endorsements are going to those currently in elected office who have a say over the state budget. I will continue to talk story and connect with all workers, whether in the public or private sector, to earn their confidence and their vote.

“I am proud to have received the Patsy Mink PAC endorsement, which supports women aspiring to leadership positions. We are indeed fortunate to stand on the shoulders of fearless trailblazers like Rep. Patsy Mink and Sen. Mazie Hirono who have come before us.”

>> Sherry Menor-­McNamara, a first-time candidate, is president and CEO of the Hawaii Chamber of Commerce.

In a statement, she said: “It’s not surprising that some of the early political endorsements have gone to career politicians in the race. … My background and credentials uniquely qualify me to effectively tackle issues relating to the high cost of living and doing business in Hawaii.”

>> Former mayoral candidate Keith Amemiya, who has been endorsed by the Ironworkers Union Local 625.

In a statement, Amemiya said that, “regardless of endorsements, voters want fresh leadership and an end to corruption and gridlock at the Capitol, and that’s why I’m running for Lt. Governor and why my message of change is resonating with people.”