Dude, seriously that seems like a terrible idea. We already have an issue with legitimate drugs.

Additionally the original argument was that cartels will seek out whatever means they can to make money.

It'll just shift their efforts towards other money making schemes, ie human trafficking or kidnapping and ransom.

But those avenues are far less profitable than drugs, and easier to stop.

Lets look at a historical example, after prohibition did human trafficking and kidnapping jump up enormously because the gangs were going to make money somehow?

Or did the number of violent crimes and influence of gangs drop off because there wasn't a huge river of cash flowing into their pockets afterwards?

Sure we have an issue with legitimate drugs. Decriminalizing will not stop our drug problem, but it will reduce our, and especially mexico's crime problem. And I, and I bet all of north mexico would rather have a drug problem than a crime problem. (For one drug's only directly affect the user, but crime affects everyone)