The Drug War industry is as entrenched as the Health Insurance grifters: neither gives an inch.
The medical facts or the historical background should be adequate arguments for ending hemp prohibition; but it's the economic counter-productivity that seems to clinch it for most of the people I talk with. Once they grasp how much they spend on policing, prosecuting, and incarcerating hemp users they're pretty unhappy, but if they can see that it's the illegality itself that makes a florist-shop or corner drug-store
product into a dangerous contraband, and the established criminals simply make a phone call to send our police after upstart competition, that seems to be the most convincing argument!
Obama has said encouraging things, but his D.O.J. has gone the other way lately. Gotta think it's the money; everywhere you look, money trumps common-sense and idealism.