It is even more ludicrous because the constitutional case law in this area is inconclusive at best. The top court's student rights cases have produced a clear willingness on the part of the court to limit the application of the Bill of Rights to juveniles. One example is corporal punishment. School children can be physically punished in ways that the courts would never allow for convicted adult felons. Juveniles charged with crimes are not entitled to a jury trial, even when they face jail if convicted.
Adults are so entitled.
More on point, the court ruled that while public schools cannot prevent students from wearing black arm bands in silent protest of the Vietnam War, they can adopt dress codes to prevent disruptions. Students do not have an absolute freedom to speak as they please. They cannot stand up in the middle of math class and recite their poetry, for instance. Long Beach's school board feels the evidence surrounding school uniforms is powerful enough to mandate their use. It is asserting its right to set school policy in order to enhance the safety and performance of students.