What small farms?
As soon as it is Federally legal to commercially grow Big Tobacco will lobby directly and thru front groups to make sure you cannot legally sell without going thru hoops and paying ungodly amounts of money to get into the game
Bet on it
Here is something many people may not realize. The prohibition on alchohol ended 80 years ago
it wasnt until last year you could legally home brew beer in all 50 states
Right, i'm not saying that there won't be a large marketshare taken up by large corporations. I'm saying that, just as in the tobacco and alcohol industries things like craft cigars, cigarettes, rolling tobaccos, wines, liquors, craft beers etc. exist, so too is it possible for smaller scale artisanal growers to supply the inevitable demand that will exist for such high-quality products.
your point about the legality of home-brewing may be an insinuation that we haven't been free to produce and consume out own alcohol even though prohibition was overturned 80years ago; however, the fact that some states hold out on updating their legislation and others are more progressive is really all your statement proves. It also didn't prevent the craft brewing industry (and now the craft whiskey industry on its heels) to begin taking marketshare back from the large brewers, vintners and distilleries. That big tobacco--and probably big cannabis/big hemp too!--will inevitably try to wrangle the political system to its own benefit (including by lobbying for greater barriers to enter the market) is a sad fact about american politics.
As to your comment about small farms--they do exist and CSA is working in some places with dedicated communities. that they haven't overcome the enormity that is agrobusiness and industrial agriculture doesn't mean that they can't or won't ever. Farmer's markets could easily become a place to sell your harvest, with the right activism and dedication.
be easy,