I personally oppose, however I understand that people make choices every day and not all choices are for the benefit of individuals. So legalizing and regulating the "responsible?" use of cannabis by adults, may balance the already existing use of the drug. The economic stimulus mentioned in the introductory text of this question should be used for drug prevention programs, teaching alternative use of time for recreation, low income families' education, building of parks and playgrounds and job training in areas of low income families dwellings. What really worries me is the young victims that are in the hands of "responsible users?"
Assuming that there is a change of behavior, meaning the person is not bound to the use of marijuana, the individual, regardless the color of his/her skin is first a human that has redeemed him/herself to a more self responsible lifestyle, deserves the chance to a restart with a blank slate.
"Medical" I understand is referred to the usage of medication under the supervision of a medical doctor, not self medicated. (The above question refers to planting your own plants? how many plants are enough? How many people would have to be hired to control the amount of plants for each individual? I would rather approach an alternative type of therapy).