Just four years after then-Mayor Richard Riordan launched the Coalition for Kids to elect “reform” candidates to the school board, the Coalition itself faces an uncertain future.

In last week’s city primary, the teachers union pasted the Coalition, dumping two incumbents despite rising test scores, a massive school-construction program and virtually unanimous editorial endorsements for the Coalition’s incumbents.

All of a sudden, the Riordan Revolutionaries look like the Jacobins of the French Revolution: They who had formerly applied the political guillotine now find it loosed upon them. And their rival political force, the teachers union, is now victorious and claiming the mantle of true reform.

The Election Day loss of Genethia Hudley Hayes in South Los Angeles was especially stunning to Riordan. “The lesson we learned there is that you’ve got to get the vote out,” he said in an interview. “The voter turnout was so low, and the opposition got their vote out. We just didn’t do our job.”

To some degree, the Coalition and Hayes simply overlooked the possibility that Hayes could lose — and that the teachers union was likely to infuse its candidate with substantial last-minute money. But the union also demonstrated that Riordan’s forces will always suffer in elections settled by old-fashioned, volunteer-dominated, get-out-the-vote drives. Riordan has donors, not foot soldiers.

“We out-campaigned and out-organized Genethia,” said Jewett L. Walker Jr., the consultant for successful challenger Marguerite LaMotte. “You have that luxury when UTLA is endorsing you, because you have a volunteer base to recruit from, hundreds of volunteers we could touch and feel, folks who actually came into the office to make phone calls or to walk precincts.”

Caprice Young, the other defeated Coalition incumbent, realized she was in trouble in her west San Fernando Valley district. She was walking precincts even as the sun set on Election Day. But she too lacked the army of volunteers, relying instead on her mother to pick up individual voters and take them to the polls.

Riordan was especially nonplused by the union’s campaign against Young. “What the other side did was brilliant,” he said. “By brilliant I mean evil, in doing a negative campaign on her. They made her sound like the worst human being on Earth. And I guess in politics, that’s considered good politics.”

Good politics also meant successfully demonizing Riordan himself as well as his high-profile collaborator, billionaire philanthropist Eli Broad. In District 5, incumbent David Tokofsky ran as a can’t-be-bought independent, a theme that was available after the Coalition retracted its previous support of him.

“That Riordan was trying to get rid of him,” grumbled one Silver Lake voter last week after casting her vote for Tokofsky. Tokofsky finished first, too, but he’ll still have to face a Coalition-backed challenger in a May runoff.

The interpretation that Riordan’s involvement was a bad thing — something to be opposed — was commonly expressed by pro-Tokofsky voters interviewed outside polling places in Eagle Rock and Silver Lake.

In parts of South L.A. the Riordan/ Broad connotation was expressed even more darkly. “We understood that Genethia Hayes voted for some contracts that would have benefited Mr. Broad,” said one campaign worker for Hayes’ opponent. The worker didn’t want to give his name because “I don’t have enough power to confront Mr. Riordan. I am not white. It wouldn’t take much to make me homeless.”

The sentiment has valid historic roots, but it’s an ironic fit on men who’ve invested time, money and prestige into bettering the city — unlike much of the city’s disengaged wealthy, who dither or cower within their gate-guarded enclaves.

As mayor, Richard Riordan would have preferred the outright power to appoint school-board members. But unlike some other big-city mayors, Riordan couldn’t control the board because school-district boundaries extend well beyond the city of Los Angeles and into the jurisdictions of other mayors. Instead, Riordan wielded political muscle to solicit campaign funds for his chosen candidates. It helped mightily when Broad, perhaps the city’s richest full-time resident, signed on. In recent times, Broad has helped Riordan decide whom to endorse. Broad also was instrumental in recruiting former Colorado Governor Roy Romer to become the L.A. schools superintendent.

But from the start, what reform meant was never consistently clear. This new board, for example, was supposed to adopt a more corporate-style governance. That is, they were supposed to work part time, set policy and detach themselves from day-to-day operations. In fact, Caprice Young, Riordan’s protégé, personally intervened time and again to resolve problems with proposed school sites. And she frequently crafted results that seemed to justify her effort.

Riordan and Broad used their personal capital to successfully propel their fund-raising. But this personality-driven reform has yet to evolve into a community-based effort; it’s certainly never been institutionalized. And because Riordan’s not mayor anymore, his political and fund-raising pull has diminished. Indeed, critics question why Riordan and Broad get to stage their own private process to pick school-board candidates. The current mayor, Jim Hahn, has evinced no desire either to take up the call or partner with Riordan and Broad. In effect, the Coalition relies almost exclusively on the star power and commitment of 69-year-old Broad and 72-year-old Riordan. And this very celebrity is a liability with some voters, who have accepted critics’ characterization of Riordan and Broad as meddlers or, worse, as frontmen for moneyed interests.

Riordan says he’s long considered the challenge how to sustain his vision of reform. “That’s something that’s been on our minds from the Day 1,” he said. “The whole thing, like anything, is to find the new leaders. Because there’s a large group of people who are behind us, who are part of this. But to ask young people to be leaders, ready to step in, is very important.”

“You never can give up,” he insisted. “We’ve made great reform in the school district in the last four years. And for some reason, this message never got across to the public.”

The message from United Teachers Los Angeles, in contrast, was loud and clear. UTLA, as seemingly immortal as the school district itself, isn’t going anywhere — which is one factor considered by Young when she recently called for a breakup of the nation’s second largest school system.

In this campaign, union leaders capitalized on the public’s high regard for individual teachers, while mobilizing their members against board members they tarred as “anti-teacher.”

UTLA President John Perez defended this branding, pointing to the precipitous rise in administrative salaries, the widespread use of costly consultants, a high-cost school-district headquarters and the board’s recent decision to offset a budget deficit by increasing class size. “What goes on in the classroom must be the focus of the district,” said Perez. “The classroom must be the last thing cut and not the first thing. Teachers and voters want to see someone on the board who has been in the classroom, someone who has the understanding that the classroom is the primary building block of education.”

Hayes and Young countered that they were not anti-teacher. The teachers’ raise they supported was all of 1 percent less than what the teachers had negotiated with Superintendent Romer. The current school-construction program will directly benefit teachers as well as students; previous boards, with any number of UTLA-backed members, had never got this program off the ground. The current board also has expanded and organized quality teacher training. And this board replaced a superintendent who was passively hostile to the teachers union with Romer, a pro-union Democrat. On most of these recent initiatives, the Riordan-backed board members and the UTLA-backed board members actually worked in concert.

There was a striking militancy to the union’s election politicking. Much like Egyptian President Anwar Sadat in starting the 1973 Yom Kippur War, union leaders seemed determined to prove their legitimacy by coming back with something that could be called a win. After demonstrating his warrior bona fides, Sadat followed up by making peace with Israel.

Superintendent Romer is game. The day after the election he regaled depressed senior staffers with stories of elections that he’d lost, recalled one of them. And he’s also met with Perez, who offered that “Of all the superintendents I’ve known here, he is the one I really believe when he says he’s interested in improving student achievement.” Now Perez has the chance to show his own skeptics that this election was about bettering the fate of children — and not just about controlling who sits on the Board of Education.

Ben Quiñones contributed to this article.