Nine students are suing the state and teachers unions in an effort to get bad teachers out of the classroom. But the unions say tenure and seniority is there to keep talented teachers from leaving for other jobs.
The students say it's unfair that their future is compromised by what they charge in their lawsuit as grossly inefficient teachers.
"Instead of learning our subject, we sat in class coloring and watching YouTube videos," said plaintiff Kate Elliott.
Led by Dave Welch, a Silicon Valley millionaire and founder of advocate group Student Matters, they allege that five laws go too far to protect ineffective teachers.
"We have evidence that kids are losing months and months and years of education and creating a gross disparity in violating the Constitution," said Theodore J. Boutrous, an attorney for Student Matters.
Los Angeles Unified School District Superintendent John Deasy is backing the lawsuit. He says ineffective teachers are on the payroll.
"In some instances, we have employed grossly ineffective teachers and we have attempted to address those, and in other instances, we are in the process of addressing them," said Deasy.
California's teachers unions have joined the fight, aligned with the state attorney. They say multiple factors cause an achievement gap.
"Public policy changes to these laws must be decided by the California Legislature. As a matter of law, plaintiffs cannot meet their very heavy burden of invalidating on their face these five statutes," said Deputy Attorney General Nimrod Elias.
Unions say eliminating such laws would erase a vital support system for a profession that is already losing talented people to higher paid positions in the private sector.
"Our schools have been underfunded, just savagely underfunded, for the last six or seven years. And if we're going to repair the schools, we have to start by actually bringing back teaching staff," said Warren Fletcher, who heads United Teachers Los Angeles.
There are questions about what yardstick would measure a poor teacher. One of the student plaintiffs complained about one teacher in Pasadena. The defense showed a video of other students praising that same instructor, who became "Teacher of the Year" in Pasadena.
Some of the plaintiffs are expected to testify in the court battle, which is expected to last several weeks.
The trial, being heard by Superior Court Judge Rolf Treu without a jury, is the latest battle in a nationwide trend. Dozens of states have moved in recent years to abolish or toughen the standards around giving teachers permanent employment protection and seniority-based preferences during layoffs.
The Associated Press contributed to this report.