“The decision hands teachers’ unions a major defeat in a landmark case. Judge Treu agreed with the plaintiffs’ argument that California’s current laws make it impossible to remove the system’s numerous low-performing and incompetent teachers, because the tenure system assures them a job essentially for life; that seniority rules requiring the newest teachers to be laid off first were harmful; and that granting tenure to teachers after only two years on the job was farcical, offering far too little time for a fair assessment of the teacher’s skills. Further, Judge Treu said, the least effective teachers are disproportionately assigned to schools filled with low-income and minority students.”
http://www.nytimes.com/2014/06/11/us/california-teacher-tenure-laws-ruled-unconstitutional.html?_r=1