However, it is legal to advocate a change in the law. It is even legal to change the law. Promoting the use while it is still illegal is not a stance the school should take, nor arguing the advocacy of such an action.
But to effectively argue the debate on drugs, one side must take the position of advocating their use?
And bringing back an older point, if promoting illegal activities is wrong, why do movies get away with it? Why can they advocate and make appear glamourous casino robbery, or murder?