To all the answers, not to sound like a dick, I know all these and they're not the answers I was looking for.
Again, I appreciate the responses, but as pertaining to this particular question, they're wrong because they pertain to greed and racism, not exactly things people want to flaunt.
I will rephrase the question, and more in depth
What is the
legitimate reasoning that a politician gives when posed this question?
Say for example they were in a debate with another politician who knew the ins and outs of Drug Law and History, what valid reason could/do they give to this person about "Why Cannabis is Still Illegal", that couldn't be shot down by "That's just lies and propaganda" or "If/when it is legalized, the gangs fighting and killing over it will dissipate due to the fact that no one would buy something off the black market if they could get it at Wal-Mart"?

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There’s a time when the operation of the machine becomes so odious, makes you so sick at heart, that you can't take part, you can’t even passively take part, and you’ve got to put your bodies upon the gears and upon the wheels, upon the levers, upon all the apparatus, and you’ve got to make it stop! And you’ve got to indicate to the people who run it, to the people who own it, that unless you’re free, the machine will be prevented from working at all!
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