The problem with any law that alienates the state from the federal control puts is in violation of the Constitution. Article VI of the Constitution makes federal law “the supreme law of the land.” The only way to keep the feds out of an inquiry to investigation is to determine that the perpetrator has violated a law not within the scope of the feds. Otherwise, they can step in any time they want. An example of this is the, so called, hate crimes. So any deviation of the scope of the federal government will create a slippery slope and all crimes become suspect at that time. Illegal drug use is within the scope of the feds.
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