Drug legality is a question of law, and yes it is handled at the state level. Rights as in those discussed in the Constitution and its ammendments are created at a government level: some by Presidents; others by Congress; still others by the Senate. They are ratified by a majority vote of the Federal Courts.
By and large the ammendments that affect the people were created to overturn or limit decisions made by the Supreme Court. So no, rights are not determined by the Supreme Court. It is imaginable that an ammendment to the US Constitution could focus on the use of drugs, but I doubt that will happen. I suspect that will always remain an article of state law.
What determines rights in Australia? Is it Thunderdome?
So its rights by decree in America... I don't think that's feasible. More on that below.
Deucaon: I misread you; I thought you were asking why some things are considered right (as opposed to wrong) when you meant how people determine what is a right (I missed the a). In that case, you need to look into over two thousand years of social and political philosophy for other people's thoughts, posit an ideal for whoever you're governing based on whatever you decide, and determine how to enact that. I still think it's a rather silly question, but I have answered you srsly now that I think I understand your question better. I also need to point out that I distinctly said the legislative branch of government, NOT the judicial system. The courts administer justice, and at times do indeed determine the unfairness of a law after a lengthy appeals process, but the laws don't usually start there, and if the government is functioning correctly, the judicial system does not and can not legislate from the bench.
I figured that determining what is a right when it is not explicitly stated in the constitution would be a case to case basis. Its not like law makers would sit around an office all day dreaming up scenarios to determine if they can deride a fundamental human right from that imaginary experience. And if the idea of human rights is derided from experience then I think a case to case basis would be more logical.
For my part I understood your question, it just didnt deserve a real answer. I do however still say that my idea about the D&D core rulebook is far better than Thunderdome. Australia should adopt the D&D system of fundamental rights.
"Well none of you are allowed to express your opinion unless you're a member of parliament but at least you're allowed to marry a horse" said our prime minister after introducing the "JMH System" to Australian law.
And yes, it was Deuacon who first confused legislative with judicial. How those two can be switched I don't know. What determines what is a right in modern society largely goes back to social contract theory and Hobbes and Voltaire and Locke, and of course the Magna Carta, and from there to the greek states. So to find out you'll have to go all the way back to ancient Sparta. and hang around a lot of open pits.*
*Emphasis on this part. For learning.
I'm sure that Spartans would be able to determine how much privacy a person should be allowed to have when surfing online and the Normans would know if a government should allow a person to destroy themselves with narcotics. Come to think of it, perhaps we should consider Caligula's opinion on the right to bestiality or Mohammed's opinion on the right to paedophilia... or perhaps not as this isn't the Iron Age nor is it the Middle Ages so perhaps we should take the opinion of ancient philosophers with a grain of salt. Perhaps.
"I felt insulted until I realized that the people trying to mock me were the same intellectual titans who claimed that people would be thrown out of skyscrapers and feudalism would be re-institutionalized if service cartels don't keep getting political favors and regulations are cut down to only a few thousand pages worth, that being able to take a walk in the park is worth driving your nation's economy into the ground, that sexual orientation is a choice that can be changed at a whim, that problems caused by having institutions can be solved by introducing more institutions or strengthening the existing ones that are causing the problems, and many more profound pearls of wisdom. I no longer feel insulted because I now feel grateful for being alive and witnessing such deep conclusions from my fellows."
-Jimmy McTavern, 1938.