Leaders of the Los Angeles school district made a calculated gamble: The January teachers strike made such a huge, positive impact on the public that sympathetic voters, they thought, would overwhelmingly pass a tax increase to benefit schools.

They turned out, it appears, to be wrong.

While the verdict was not entirely settled late Tuesday evening, all signs pointed to a disappointing outcome for a tax measure put on the ballot by the nation’s second-largest school system.

In early returns, support for Measure EE was well short of the two-thirds majority required.

School district officials and their allies, including L.A. Mayor Eric Garcetti, had envisioned Measure EE as a crucial building block in reshaping the district, an effort they had hoped would include a major cash infusion.

But instead of a celebration, the speeches at a Tuesday night rally sounded a consistent theme of: “We’ll get ’em next time.”

“We’re not going anywhere,” Garcetti said at a Tuesday night rally in Boyle Heights. “Pass or not, tomorrow we roll up our sleeves and continue that work.”

Opponents of the measure were cautiously celebratory.

“We did our best to run an honest campaign to let voters know that Measure EE was a massive tax increase,” said No on EE campaign spokesman Matt Klink. “It’s early but so far the results look good.”

The parcel tax bid was an aggressive change of direction for district leaders. They had narrowly rejected this very strategy less than a year earlier as unlikely to succeed until L.A. Unified demonstrated financial and academic progress. They also spoke of choosing an election date likely to have a higher and more liberal turnout, to give a tax measure a better chance of succeeding. And they wanted plenty of time to run a campaign. They were pointing toward the presidential election year of 2020.

That logic changed after the six-day teachers’ strike in January, which seemed to generate broad support for the issues raised by teachers, including their advocacy for more education funding.

Based on promising polling, Supt. Austin Beutner put aside his previous caution and urged the Board of Education to make the try.

On Tuesday night, standing at Garcetti’s side, Beutner predicted the effort would ultimately pay dividends, regardless of the results of this election.

“We’ve put together the broadest, deepest, most diverse coalition in support of public education in our community in a generation,” he said.

Measure EE would impose a levy of 16 cents per square foot of indoor space on a property, excluding parking areas, and raise an estimated $500 million annually over its 12-year term for the district.

Los Angeles Unified School District officials say money from the parcel tax is badly needed to provide more resources and staffing to classrooms. They point to much higher spending levels for schools in New York City and other large urban areas. The school system also needs more money to deal with a long-term projected funding shortfall, which is exacerbated by commitments to pay for retiree health benefits and pension obligations.

Opponents say the district must demonstrate better use of the money it has and that the tax increase would hurt families and businesses.

“I think the school district is mismanaging how they spend their money and mismanaging how they create a quality education for all their kids,” said Richard Fisk, of Granada Hills, chairman of government affairs for United Chambers of Commerce, based in the San Fernando Valley.

Before asking for more money, “the district needs to get its house in order both fiscally and academically,” he said.

Alex Tsimanis said he voted “yes” because he believes that L.A. Unified “is woefully underfunded compared to similarly situated school districts across the nation.”

Tsimanis, 46, lives in Playa Vista and has a 10-year-old in a local public elementary school.

It never looked to be an easy win, especially with the two-thirds vote requirement.

“It is a very high threshold. It’s easier to count to 34 than it is to 67,” said Garcetti, alluding to the two-thirds requirement. “In most democracies, in most states, even redder states … it’s a simple majority.”

Garcetti said he was hopeful because local voters had surpassed the two-thirds mark on recent funding measures affecting parks, transportation and homeless services.

Across most of the sprawling school system, the tax measure was the only item on the ballot — meaning that L.A. Unified had to bear more of the cost of the election — an estimated $12.5 million. In addition, the district set aside up to $1 million for an “information campaign” that, under election rules, is supposed to stop short of directly urging people to vote for the measure.

The money spent on the election “could have bought a ton of needed school classroom supplies and helped with teacher salaries,” Warren Cereghino, a Pacific Palisades resident, said in an emailed comment. “Even here in the ‘upscale’ Palisades our three elementary schools, one junior high and one senior high always needed supplies while our two sons were proceeding through the system.”

The slim ballot likely depressed turnout, especially following a May school board election. Low-turnout elections generally bring out a disproportionately older, more conservative, less tax-friendly electorate.

The time frame for the campaign was tight, but supporters assembled a wide-ranging coalition that raised about $8 million. Two powerful employee unions combined forces, providing volunteers and financial backing: United Teachers Los Angeles, which represents teachers, nurses, counselors and librarians, and Local 99 of Service Employees International Union, which represents a comparable number of employees that includes cafeteria workers, bus drivers, classroom assistants and security aides.

Leaders of both unions also were present at the Tuesday night rally.

“Everyone is talking about what our students need,” said teachers union leader Alex Caputo-Pearl. “That is a win.”

“It is time to stop and reverse the chronic underfunding of public education,” said Local 99 Executive Director Max Arias. “Tonight is the night it begins,” he predicted.

Community groups generally supported the measure, as did some key local businessmen and philanthropists, including Clippers owner Steve Ballmer and philanthropist Eli Broad.

Although opponents failed to raise nearly as much, they had enough to get their message out. Funding for the opposition came primarily from taxpayer organizations and local groups representing business interests, including the L.A. Area Chamber of Commerce, the Valley Industry & Commerce Assn. and BizFed.

Opponents also generated attention by capitalizing on a district stumble — a last-minute change to the wording of the measure that made it seem, to critics, as though officials were trying to expand the tax without appropriate public scrutiny.