I think every state should have its own right to legalize marijuana, whether it be for medical or recreational use, it should be the states decision not the Judicial department. The war on drugs is being lost, so why not legalize it and use it as a tax source that way taxes will be lessened on normal workers, and revenue can help each state out, if they decide that is what they want.
States have the right to make laws regarding taxation, education, and a myriad other things. Why then would states not have the right to create their owns laws as to the legality of substances. Of course there would be federal backlash. In Minnesota, for instance, the drinking age was 19 until 1983, when federal pressure, in the form of withholding of transportation funding, convinced the state legislature to bring the law in-line with the federal government. This did not mean that the state law was illegal, only that the federal government got it's way.