Voters rebuffed a vicious $2 million campaign by the Hawaii Carpenters Union to defeat Rep. Sylvia Luke in the Democratic primary for lieutenant governor, in retaliation for her refusal as House finance chair to permanently extend the 0.5% excise tax surcharge for the union’s cherished Honolulu rail project.

But the carpenters’ failure to defeat Luke doesn’t mean the battle is lost to extend the rail tax — at least enough to finish the commuter line to Ala Moana Center.

After overruns during previous administrations left rail $2 billion short of reaching Ala Moana, Mayor Rick Blangiardi and the Honolulu Authority for Rapid Transportation sent a pending $10 billion recovery plan to the Federal Transit Administration that would stop two stations short of Ala Moana in Kakaako.

That followed clear signals from state legislators led by Luke that they wouldn’t rescue HART again after it didn’t keep promises from two previous bailouts totaling $4 billion.

Rail leaders, however, continued to express hope the GET surcharge would ultimately be extended to allow rail to expand to Ala Moana and beyond, and they might have a shot after the election.

Luke’s departure as House finance chair to run for LG removes the most powerful skeptic in the Legislature of more state money for rail.

Those who succeed her will think twice before drawing the carpenters’ ire and millions of mudslinging dollars directed at Luke and other rail dissenters before her.

If Luke is elected LG on the Democratic ticket with Josh Green as governor, she’d still have a voice, but final say would rest with Green, who benefited from critical carpenters support in his runs for lieutenant governor in 2016 and now governor. As LG he appointed a union lobbyist his chief of staff.

I asked his position on a temporary or permanent extension of the rail tax, and Green said, “If we do extend rail to Ala Moana, which would likely mean extending the duration of the 0.5% GET tax, we have to have more transparency, accountability, oversight, and controls over spending. We need to know we are getting our money’s worth for big projects.”

It should be a moot point until the city resolves its recovery plan with federal overseers and shows it has gained control of major open problems, such as the Dillingham Boulevard “mauka shift,” cracking guideway supports and train wheels that don’t fit the tracks.

Tax extension or not, state oversight of spending cited by Green gains importance as the city tries to skip out of oversight from the last bailout even as problems persist.

There’s little transparency; Blangiardi says he can’t discuss the recovery plan because of federal restrictions, and HART routinely answers “no comment” to simple media inquiries — and even some questions from its own board and the City Council.

Permanent extension of the rail tax could end all accountability, amounting to an endless slush fund that enables rail officials to conceal major problems that seem to become public only when they must ask for more money.

Reach David Shapiro at volcanicash@gmail.com.