This week, a California judge issued a ruling which said that teacher tenure effectively violates the civil rights of students. The ruling is a major blow to teachers unions, who are now gearing up for a fight to maintain the status quo.

Judge Rolf M. Treu wrote that tenure imposed “a real and appreciable impact on students’ fundamental right to equality of education.” While any teacher can be fired in theory, he found that the system for dismissing a teacher was “so complex, time consuming and expensive as to make an effective, efficient yet fair dismissal of a grossly ineffective teacher illusory.”

For this reason, Treu characterized the state’s position in the case as tantamount to arguing for the “de facto retention of incompetent” teachers. He concluded this position was “unfathomable and therefore constitutionally unsupportable.” In particular, the judge decided the tenure rules “disproportionately affect poor and/or minority students.”

Judge Treu’s decision was called a “major defeat” for teachers unions by the NY Times. It immediately ends the current tenure system and requires that teacher quality be considered (rather than simply time on the job) in the case of layoffs.

The ruling was praised by the plaintiff’s attorney, who called it a “landmark ruling” and “a wonderful day for California students, the Calfornia education system, and the rule of law.” Reform advocate (and frequent union foe) Michelle Rhee hailed it as “groundbreaking.” Secretary of Education Arne Duncan seemed to welcome the decision, saying it was “a mandate to fix these problems.”

Teachers unions vowed to appeal the ruling. Randi Weingarten, head of the American Federation of Teachers, told CNN’s Wolf Blitzer her group would fight the decision, saying it was, “the wrong solution to some of the right problems.” Josh Pechthalt, President of the California Federation of Teachers, said, “We have a high degree of confidence that we will prevail on the appeal.” Dennis Van Roekel, president of the NEA, said, “This lawsuit was never about helping students, but is yet anotherattempt by millionaires and corporate special interests to undermine theteaching profession.”

The LA Times reports that appeals of the decision could continue for years to come.