But advocacy groups that focus on teacher quality, school improvements and parent empowerment say the union's might in Sacramento blocks any serious change in an education system that is failing California's students. After years of battling unsuccessfully to pass accountability measures in the Legislature, those groups have turned to the courts.
In lawsuits against the state and the Los Angeles Unified School District, they allege that a number of union-backed laws "prevent school administrators from prioritizing or even considering the interests of their students" and perpetuate gross inequalities in California's education system.
California teachers have one of the shortest probationary periods in the country — lifetime tenure after two years in the classroom. If they are subsequently disciplined, an arduous dismissal process begins that can require years of paperwork and hearings before a teacher can be fired.
Dismissals are often overturned by an appeals panel made up of a judge and two educators. Layoffs due to budget cuts are based on seniority, without regard for job performance.
"We are challenging a system that was fashioned by special interests and has burdened our schools with an inflexible environment for hiring and retaining the best teachers," said Dave Welch, a Silicon Valley entrepreneur and founder of Students Matter, the main backer of one lawsuit.
CTA says such efforts are misguided. The union argues that the real problem is California's perpetual financial crisis and under-funding of public schools. At a quarterly meeting of the union last year, Vogel called on teachers to back the governor's plan to raise taxes, boasting of CTA's muscle.
"You know why people are so afraid of us? We are in every single community in this state," he told the crowd. "You cannot walk into a church in California without a CTA member being in that congregation. You can't sit at a soccer game without sitting near a CTA member. Try to be in a Safeway somewhere without a CTA member there."
The union didn't always have such clout. Founded in 1863, CTA long saw itself as a professional organization, separate from the politicized ranks of organized labor, said Alice Huffman, a former director of governmental relations for the group. It wasn't until the 1980s that CTA became a force in Sacramento.
The group began to dole out large sums of money for lawmakers' campaigns, marshaled teachers around their collective bargaining rights and ultimately fashioned itself into the main cash machine for California's Democratic Party.
It solidified its role in the Capitol in 1988 with the passage of Proposition 98, the education funding guarantee. Nearly 24 years later, CTA is deferred to as the complex law's final arbiter.
Some legislators resent CTA's power, particularly on budget issues, where it is most keenly felt. Almost none will say so publicly, citing fear of retribution.
When Perata, the former state Senate leader, wanted to tinker with education funding some years ago, CTA deluged his constituents with critical mail and put up billboards in his district that read SHAME ON YOU.
In the Assembly, where most legislators start their Sacramento careers, a onetime CTA lobbyist has long directed policy as the speaker's top education adviser. The union's allies are appointed to key committee posts in both houses.
Former Assemblyman Juan Arambula said the union is the Legislature's guiding force in the era of term limits. "CTA is going to be around regardless" of who leads in the Capitol, he said.
A few years ago, Arambula wanted to give some districts more authority to improve low-performing schools. Opponents, including CTA, did not want to give locals that flexibility.
A CTA lobbyist came to his office and told him to drop the measure, said Arambula, an independent from Fresno who left the Democratic Party over conflicts with labor unions. He refused, but "I could not dynamite that bill loose" from a key committee, he said, and it died there.
The committee's chairman was Tom Torlakson, now the state schools superintendent. Torlakson won the statewide office in 2010 with major backing from CTA, which spent more than $3.3 million on his behalf in a close three-way race.
Seven weeks ago, state Sen. Alex Padilla (D-Pacoima) took on the union in what his supporters, including the Los Angeles Unified School District and the California School Boards Assn., viewed as a reasonable response to the sexual abuse scandal at Miramonte Elementary School in Los Angeles. He proposed speeding the dismissal process for teachers who engaged in "serious or egregious unprofessional conduct": offenses involving sex, drugs or violence.
Teachers and union lobbyists who opposed the lawmaker packed a Capitol hearing room as he testified before the Assembly Education Committee. They had already paid visits to most of the committee's 11 members, posted photos of some of those meetings and thanked the lawmakers on Twitter.