Barack Obama will most likely exploit the issue of medical cannabis for his re-election-campaign.

Barack Obama probably used to be man of beautiful and human ideals, ideas, visions, and dreams- when he was young. But honestly, do you seriously think that any President of the United States of America can independently enforce or implement his political agenda? Since Obama got his campaign sponsored by the banking-lobby (amongst others), he wouldn´t have the independence to do as he pleases - even if Obama was allegedly another reincarnation of Kennedy. But a President gotta do, as he is told to do - this is reality. In the end, the President - like any other highly political position -  is just the executive organ of the military- industrial-banking lobby. We need to accept this fact. Now, what will the American citizens do? I hope they don´t rely on religiously dogmatic prayers. Politicians, lawmakers, or the President do not ordinarily listen to facts, rational reasons, or scientific arguments. This massively corrupted system - like everywhere on the world- can only be forced by pressure. Pressure can only be produced by the people, masses of people. If Obama (and hopefully his advisers) are convinced that the issue of medical cannabis could be a decisive factor and tipping point for a successful re-election, then Obama will undoubtedly must take a firm position not only on the issue of medical cannabis, but also on the issue of cannabis-legalization in general.
Once the legal framework of cannabis is radically changed in the USA, it will inevitably have dramatic drug-political and economical repercussions in the EU and beyond. Eventually, the UN single convention on narcotics and pertaining internationally ratified treaties and national drug-laws will require an overall rescheduling and reforms. The money and the different supportive military-executive-industrial lobbies involved around the "War on Drugs" add up to many trillion dollars worldwide. The "collateral" (health, social, economic, and human) damages caused by this insane and with tax-money massively subsidized "War on Drugs" are beyond our imagination. People, please wake up, and demand from your lawmakers scientifically based, sustainable, and human drug-laws for any psychoactive plant whatsoever. Governmental (quality-) control, scientific education on all psychoactive substances (including nicotine and alcohol!) in schools, absolute advertising-prohibition for all drugs, no consumption in public (schools) and committed taxes should be the most important and supportive pillars of a legal framework. Inform yourself with the facts and become active by pushing your lawmakers, who are getting paid from your tax-money, for which you have been working so hard!