Schools need not and should not limit student rights to the maximum extent legally permitted. They should engage in serious ethical analysis and do the right thing, which often means protecting and promoting student rights beyond what the law requires.
Radical education and radical politics do go together, because they both challenge the model of the person and the relations among them. So those suspicious of our president because of his ties to such a radical thinker may be somewhat correct.
Even if we carefully keep in mind the wide range of formal and informal activities that comprise "education," the question regarding its purpose still misleads. The Question implicitly assumes that education does, in fact, have a purpose.