Who’s in favor of a stronger public education system? All hands go up.

However, when it comes to a determination of how that system gets funded, public opinion becomes far more nuanced.

This means that the simple formula proposed by the state teachers’ union — a 1 percentage point increase in the general excise tax (GET) to fund a specific education agenda — is likely to stall out in the coming legislative session.

That’s the probable outcome because a tax increase in an election year is an extremely heavy lift. But it’s also the best outcome for this session, because an open-ended increase in such a broad-based tax for a restricted purpose is not a wise approach to budget planning.

The proposal is being championed by Corey Rosenlee, the president of the Hawaii State Teachers Association. The bill is still being drafted and was not available for review, but Rosenlee described its elements to Nanea Kalani, Honolulu Star-Advertiser education writer.

Rosenlee told Kalani he acknowledges that “the biggest negative of an increase is that the GET is regressive.” It tends to disproportionately affect lower-income residents because it increases the cost of items that represent a relatively large share of their household budgets.

To offset that, he said, the bill would propose increasing the state’s refundable food/excise tax credit — those earning less than $50,000 a year are eligible for that — as well as tax credit for renters earning less than $30,000.

And to replace the loss of that revenue in the budget, he said, the bill would revive an income tax on those earning over $300,000 annually — a provision of Act 60, which expired last year.

What’s missing here is that the GET not only affects the poor. It also puts a strain on business, because it’s applied at every transactional stage of commerce, compounding costs.

That’s the same complaint raised about the GET surcharge underwriting the rail project on Oahu. The difference is that there’s a sunset date for that tax, and it’s financing an infrastructure improvement that will serve everyone paying into it.

HSTA’s proposal sets out specific policy and operational fixes that the teachers favor, some of which could be enabled by the estimated $750 million the tax increase would yield each year.

It specifies: more competitive salaries for teachers; capping class sizes; ending high-stakes testing that links test results with teacher evaluations; expanding public preschool; improving facilities; increasing time spent teaching the arts; and increasing supports for special-education teachers.

Each of those items merits a separate discussion. Although financing more-competitive teacher salaries enjoys wide support, other ideas, such as the notion of de-linking testing and teacher evaluations, would draw opposition.

Above all, many of these constitute policy changes that are the jurisdiction of the state Board of Education, not lawmakers.

Rosenlee cited a poll the union commissioned of Anzalone Liszt Grove Research, a public opinion research firm. It was conducted Oct 7-11 among 500 respondents.

Those for or against the tax increase each comprised 48 percent of the total, but support rose to 57 percent when the funding targets were explained, according to a summary of the poll results.

That’s not enough support to serve as a mandate for something as economically consequential as tinkering with the GET.

A permanent increase in a tax that affects everyone should pay for the full range of public needs, rather than be sequestered for an agenda lacking in true public consensus.