Section 8, clause 3 of the Constitution states: "to regulate commerce with foreign nations, and among the several States, and with the tribes of Indians." » Many people misunderstand this clause because it is very vague, but it means that the federal government can regulate the commerce of the states if they trade with each other. “Purely local activities therefore remain beyond the reach of Congress under the Interstate Commerce Clause. » Commerce Clause states have the right to regulate marijuana within their own state. This clause gives states the power to trade goods provided they do not trade them with others.