In many ways, California is a marijuana pioneer. It became the first state in the nation to legalize medical cannabis in 1996. In the years since, however, voter initiatives seeking to legalize recreational use have failed, including in 2010. Proposition 64 would make pot legal, and establish cultivation and sales taxes. Proponents say the measure would bring billions of tax dollars into the state. Opponent fear legal pot could lead to more highway accidents and put small-time pot farmers out of business.