Legislators in Rhode Island are considering a plan to decriminalize pot, and a group in Nevada is pushing an initiative that marks the state's fourth attempt in a decade to legalize the drug.
Lawmakers in Washington state recently killed a plan to legalize the sale and use of marijuana, though lawmakers there did expand the pool of medical professionals who could prescribe the drug for medicinal use.
The ballot measure in California would allow people 21 years and older to possess up to one ounce of marijuana, enough for dozens of joints. Residents also could grow their own crop of the plant in gardens measuring up to 25 square feet.
The proposal would ban users from using marijuana in public or smoking it while minors are present. It also would make it illegal to possess the drug on school grounds or drive while under its influence.
Proponents of the measure say legalizing marijuana could save the state $200 million a year by reducing public safety costs. At the same time, it could generate tax revenue for local governments.
Law enforcement officials are promising a vigorous fight to ensure that marijuana never becomes legal in California. They believe legalized marijuana would increase crime and violence, deepen the nation's drug culture and lead teenagers to abuse pot.
The California Police Chiefs Association, Mothers Against Drunk Driving and groups such as the youth-oriented Drug Abuse Resistance Education also plan to oppose the idea.
Not everyone in law enforcement is opposed to the measure, however.
"We believe by voting for that initiative you can actually save lives," Cole said.