This step is such a radical move for a neighbour of the USA, and such a positive example for the rest of the world, that it hardly seems fair to bitch about it...
... but what does this proposed law actually accomplish?
"WOO HOO, IM GOIN TO MEXICO GET FUCKIN BAKED DUDE!"
If you can have no more than one hit of acid, a line of coke, or whatever on you at any time without being prosecuted as a dealer, and if dealing is still illegal, then it shouldn't be any easier to get [drug of choice] down there than it is wherever you live. Unless you live in southern Iowa (just kidding).
The only thing it does is take the pressure off the casual user: the end user is no longer a criminal. This is an amazingly positive step.
But it doesn't solve bigger problems: control of supply of most "hard" drugs by organized crime and the violence & gangsterism that the black market economy imposes; the major problem of quality control / purity of supply; the problem of education & public awareness of the effects of drugs and the destigmatization of users; and the constant problem that the now-not-a-criminal end user faces - how to score.
I've been thinking about the legalization issue for a while now, and the only thing that makes sense to me is to make everything completely legal and regulate it like alcohol & tobacco. Train government employees to run the stores (much like government liquor stores in most parts of Canada) - make them as highly trained as pharmacists - so they can talk to people about what they're buying & answer questions in a reasonable manner, and if there are out-of-the-ordinary dangers associated with the use of a substance, to inform the user.
No more Raid on your weed. No more crap "XTC." No more DOx sold as LSD. Cut the scumbags out of the equation and make 'em get real jobs. Let the righteous dealers get first crack at the "pharmakocist" jobs that will open up, to compensate them for the disruption of their personal economy and to thank them for keeping the flame alive through the dark years of prohibition ...
Well, I can dream, can't I?