That certainly is very true, and butterflying DuPont & Hearst would be helpful(greatly so on the national level!), but unfortunately, it will be far from the end-all, be all. Racism did still play a major role in getting recreational marijuana banned on the state level in several states, particularly that against Chicanos, in the Southwest, at least, and given that there was plenty of hysteria concerning Chinese and Blacks having interracial relations with white women, supposedly because of the use of this drug, in these areas and some other places, I still don't think marijuana prohibition would be entirely butterflied, especially not in those areas south of the Mason-Dixon Line(basically Virginia and the Carolinas going west past Texas and including N.M. & Ariz.)
Getting rid of the prohibition on the national level wouldn't be too hard, with the right PODs. Unfortunately, it will be much, much, harder to do away with local & state prohibition. One scenario I can see possibly happening here is the tobacco and booze industries heavily lobbying in favor of statewide cannabis(though not necessarily male hemp as well) prohibition in certain states, particularly in places such as North Carolina, Virginia, and Kentucky where tobacco was practically king-of-the-hill as far as cash crops went. I can also see the equivalent of wet and dry counties across states where total prohibition of cannabis isn't as likely to occur, such as Iowa, Kansas, or Nebraska. It may even fail completely in some areas, like New England & New York, or the Pacific Northwest, where racial fears tended to be at the mininum for the era........in fact, if a significant Latino, particularly Mexican influence, can develop in New York City(and it was fairly noticeable IOTL), it may actually become a center for "stoner culture", kind of like how San Francisco did IOTL, but just with different circumstances.
Hopefully the more egalitarian US of this timeline won't have the same issues with cannabis via racist fearmongering, but I fear you may be right. Ironically, cannabis plantations DID exist in the parts of the South you mention (albeit for hemp fiber cultivation), given that the Upper South never was well suited for cotton growth the way the Gulf States are/were. However, you are also correct in that King Tobacco pretty much ran the show in VA, the Carolinas and KY/TN. How relations evolve between the "mainstream" US population (read; whites) and Mexicans would likely presage how this issue unfolds. I will admit bias here for inclusion (however delayed) of the South in legalizing cannabis for two reasons;
1) I L.O.A.T.H.E. William Randolph Hearst beyond the issue at hand, and anything that would take him down any number of pegs makes me feel warm and toasty inside. And,
2) Growing up in VA, and residing pretty much in the rest of the South my whole life, recreational use of marijuana always seemed the rule for people in my age group rather than the exception. Granted, times were different way back when, so chalk it up to a bias of personal experience.
MacGregor,
I would advocate options 2 or 3, although I wouldn't be opposed to 1 either; anything which adds more detail builds the world one creates. Also, welcome back to teh Interwebs!