Now that many states have legalized both medical and recreational marijuana, it's time for the federal government to follow suit and realize that the times have changed significantly. Having conflicting state and federal laws simply creates confusion and is bad policy. It's time for the federal government to dicriminalize weed and let the states make their own choices.
People should have the right to freely associate and demonstrate, both rights that are constitutionally protected. Furthermore, in a state where marijuana is legal, a trifecta of rights are violated by attempting to disperse the demonstration. They aren't hurting anyone. They're protesting and partaking of a legal substance. Let them be.
The challenge should be illegal. Encouraging people, especially young people, to do drugs recreationally, sends a message that our society doesn't care about its youth. It should be illegal because pot is still a gateway drug and can cause lung cancer, car accidnts, and poor judgement. We should be encouraging young people to find other ways to enjoy life.
This would be like a state allowing the drinking age to be 15 or any other weird laws it wants to change and then expect the federal government to abide or allow it. If the school receives any federal funding then they absolutely should not be allowed to do something that breaks federal law.