Former U.S. Surgeon General Joycelyn Elders defended the measure on CNN Sunday, saying that much more harmful substances, such as tobacco and alcohol, are legal, and marijuana should be no different.
"I don't think much could be worse than the present situation that we have, when we have the highest number of people in the world being criminalized [for] many nonviolent crimes relating to marijuana," she said. "Marijuana has not caused anybody directly to die. It's not a toxic substance that would cause people to die and ... we can use our resources so much better."
But politically, marijuana remains a potent issue. The California Democratic Party hasn't taken any position on Proposition 19, and virtually all heavy hitters are opposed to it, including Sen. Dianne Feinstein, Sen. Barbara Boxer, and both gubernatorial candidates.
This is not the first time that a state has dabbled in such a measure. Earlier this year, a marijuana-legalization bill was introduced in Washington, but it was struck down by the state legislature.
But California has been known to lead the country in marijuana laws. It was the first state to legalize medical marijuana, and over time, the state has relaxed its laws governing marijuana.
Last week, Gov. Arnold Schwarzenegger signed a law reducing the charges for 1 ounce or less of marijuana possession to a misdemeanor from an infraction, essentially saying that those found in possession wouldn't face arrest, a court appearance and a criminal record.
While legalizing marijuana remains a hot-button issue, Americans' views toward medical marijuana have softened in recent years, and more states are paving the way for legal use of marijuana for medicinal purposes.