“States are not defying federal marijuana laws by legalizing pot in their state.”
Federal law prohibits the recreational use of marijuana. California state law purports to make it legal.
California has set up state agencies to regulate the production and sale of marijuana. They license people, under the color of law, to do things that violates federal law. California even taxes marijuana to bulk up state coffers.
And you write that California is not defying federal law.
Your view is not credible.
Federal law is enforced by the federal government, not state governments. If the DEA want's to arrest someone for smoking a joint then they have the authority to do so and California cannot interfere with them.