Hard to say. Its outlawing in the mid-twentieth century was a somewhat random event in a way, though the prevalence of anti-marijuana legislation around the world today suggests more pervasive factors at work.
To venture a guess, in the next two decades cannabis will be legalized in a number of nations. And while this may be an advance viewed from the perspective of personal liberty, it will happen partly in order to enhance governmental political control/social stability. (Cf., the drug 'soma' in Huxley's "Brave New World.") Despite the fears of 1930s drug prohibitionists, really serious stoners don't tend to riot--much less organize.