When all else fails, sue. That's the lesson from Los Angeles, where the ACLU filed a lawsuit to end the district's "last hired, first fired" layoff policy.

The suit came about after layoffs in the spring of 2009 gutted more than half the staff of three of the city's neediest schools, while wealthier schools were unaffected. This was because Los Angeles used a district-wide seniority calculation for laying off teachers. Consequently, schools with the highest turnover--and also the neediest populations--were hit the hardest.

While California law cannot be held harmless here--it does require districts to use seniority as the determining factor in layoffs--it does not dictate whether seniority is determined district-wide or within each school. That's a decision set forth in the Los Angeles teacher contract. State law also provides flexibility to its seniority rules, allowing exceptions for either "pedagogical reasons" or to ensure students' rights to a quality education.

An initial ruling in the suit this past May protected the original three schools from layoffs, but this recent court settlement goes a step further: up to 45 of the most struggling schools (about 6 percent of the 792 schools in LAUSD) will be protected from layoffs entirely. The remaining schools will begin using school-based seniority calculations, resulting in much fairer practice. The settlement is pending final approval from a judge.

While seniority will remain a significant factor in determining who gets laid off at the majority of LA's schools, the settlement is a fair compromise to eliminating seniority completely. The union should be happy this is as far as things went. Stay tuned for repercussions in other Golden State school districts.