Oahu rail has become the monster that eats mayors — real and would-be.

The main narrative from the primary election for Honolulu mayor was that voters favored new faces Rick Blangiardi and Keith Amemiya over political veterans in these uncharted times, and that’s certainly true.

But another key factor was that the losing veterans — Mufi Hannemann, Colleen Hanabusa and Kym Pine — all were tainted by the city’s $9.2 billion rail disaster.

Hannemann initiated the project, winning approval from the City Council and funding from the Legislature after those before him had failed. He got a referendum of approval past a skeptical public by barely half the vote.

It made him the primary face of the project’s overpromising and underdelivering, and his efforts to pass blame to his successors never resonated.

His fifth-place finish for mayor, after two lopsided losses for governor and one for Congress, appears to derail any hope for further political relevance.

Hanabusa served for 10 months as chairwoman of the Honolulu Authority for Rapid Transportation, and actually did a decent job of instilling some semblance of transparency and truth-telling.

But voters held any association with rail against her; as she correctly predicted when she reluctantly took the HART post, there was no upside to getting involved.

Pine was an unabashed promoter of rail as a state legislator and city councilwoman, voicing few concerns about the mounting cost overruns and managerial incompetence.

She tried to position herself as somewhat of a rail critic after deciding to run for mayor, but voters didn’t buy it.

These three aren’t the first casualties of rail at the polls. Hannemann’s successor, Peter Carlisle, was soundly defeated for reelection after two years of cartoonish cheerleading for rail as it sank deeper into trouble.

Current Mayor Kirk Caldwell, Hannemann’s managing director and staunch ally on rail, was elected on a false “Build Rail Better” promise only after Pacific Resource Partnership — an alliance of the Carpenters Union and construction industry — ran a $3 million smear campaign on his behalf against former governor and anti-rail candidate Ben Cayetano.

The betting here is that if Caldwell proceeds with his plan to run for governor in 2022, voters fed up with rail will be waiting to give him the same smackdown they gave Hannemann and Carlisle.

Blangiardi and Amemiya both generally support finishing rail to Ala Moana Center, but have offered few specific ideas for dealing with the big financial hit rail is certain to take from shrinking tax revenues in the coronavirus pandemic.

The general election may well turn on how ably the candidates navigate between voters disgusted with rail’s ever-escalating price on one side and big-money special interests like PRP on the other side making themselves loudly heard in favor of full rail build-out at any cost.

Reach David Shapiro at volcanicash@gmail.com.