i believe it would be very simmilar to when they tried to ban alcohol. what happened was people making it themselves then selling it on the black market making the gangs profit and the government get no payoff from taxing it.
there would also be a huge uprising from smokers if it was banned, imagin hundreds of thousands of nicotine craving smokers going nuts and being angry. not even god could save us.
e cigs are bannable because they are new and dont have a widespread knowledge on them. if they are going to ban them they will do it quickly before it catches on.
its not always a bad thing though if you still
vape when its ilegal, prices would hit the floor for exsample if they legalized weed in many countrys the price would skyrocket just due to taxes and regulations on it.