Public education was one of the big issues under discussion in 2008 when Hawaii voters last faced a ballot question to convene our first constitutional convention since 1978.

One hot topic was whether Hawaii’s statewide school system, the only one of its kind in the nation, should be decentralized and rebuilt around the schools and their communities. Advocates felt legislative efforts to shift decision-making and resources from the state office to the schools came up far short.

Other potential agenda items included a dedicated source of schools funding to support greater student achievement and more pay for educators, as well as measures to hold teachers, principals and administrators more accountable.

A leading opponent of a 2008 constitutional convention was the teachers’ union; its lobbying arm, the National Education Association, donated $350,000 to the successful anti-ConCon fight.

Ten years later, a ConCon question will again appear on next month’s general election ballot, and once again, the Hawaii State Teachers Association has joined with fellow unions and other groups in an ad campaign against it.

It’s a good reason to view with skepticism a separate HSTA-sponsored constitutional amendment on the ballot that would allow the state to tax investment properties to finance teacher pay raises.

New taxes of such magnitude should come from open community discussion and objective vetting, not an HSTA power play to politically muscle its amendment through the Legislature without the usual scrutiny from House and Senate money committees or weighing it against other ideas to fix our schools.

We spend nearly a quarter of the state general fund on education, raising a vital question of whether the struggles in our public schools are a result of not enough funding or money not spent wisely.

We should have a clear answer to this question before a major tax increase is imposed for the schools, and any new taxes should be part of a broader plan to identify and prioritize all of the needs of public education — not just the interests of teachers.

And higher taxes to support education shouldn’t come at the expense of the counties, which depend on the property tax — the only major tax they control — to fund their operations. Public education here is a state function, and there are more than a dozen existing state taxes the Legislature could use to raise money for education.

A tax measure of such importance shouldn’t be hidden behind vague wording that gives voters little information about what they’re approving and leaves the Legislature with broad discretion to tax nearly any property by any amount it wishes.

If the teachers’ union wants to amend the state Constitution to facilitate pay raises, it could support a constitutional convention and let its proposal be properly considered alongside all the other priority needs of public education.

Reach David Shapiro at volcanicash@gmail.com.