lets just say that they do have this debate. and for some far out crazy reason the prohibitionist win. how much damage do you think it would cause on the legalization side?
They won't win. If they actually let each side have a fair amount of speaking time and enough time to show evidence, the legalization movement will win. Prohibitionists base their argument off stereotyping smokers and studies and from the '30s and 40's which have absolutely no ground in our world because of the way they were conducted. As long as our side doesn't go dressed like a bunch of retards we have a huge chance of winning. Sadly image means everything to the American public.
Don't worry about this at all man. The people debating will be very well prepared and will come with the recent studies that will disprove any bullshit that the prohibitionists spew.