Voters are about to decide if Californians will be able to legally possess an ounce of marijuana, grow up to six plants and purchase retail marijuana, all without a medical recommendation.

It’s not the first time recreational use of pot has been on the ballot. Californians rejected a similar proposition in 1972 with 66% of the vote. Most recently, in 2010, Proposition 19 likely failed because of regulatory issues within the measure and because a law signed by then-Gov. Arnold Schwarzenegger may have eroded public support.

Section of a sample ballot from the 2010 general election. (L.A. County Registrar-Recorder/County Clerk)

Proposition 19 would have allowed local governments to regulate and tax recreational marijuana two years before Colorado and Washington passed their measures. The proposition qualified for the ballot in March 2010 and early polls had the measure leading narrowly. But opposition grew steadily over the course of the year.

The Los Angeles Times editorial board found it "badly crafted" and "poorly thought out" and declined to endorse it. Schwarzenegger as well as current Gov. Jerry Brown, Sens. Barbara Boxer and Dianne Feinstein and current Atty. Gen. Kamala Harris opposed it. Polling showed declining support and ultimately the proposition failed, 53.5% to 46.5%.

How the Los Angeles area voted

That September, the Legislature had passed a bill that reclassified the possession of small amounts of marijuana to a civil infraction, weakening one of the main arguments for the proposition. Schwarzenegger signed that bill into law a month before the election, which may have left some voters feeling that the proposition was no longer necessary.

Proponents claimed that, under existing marijuana laws, arrest records for small amounts of marijuana ruined lives, especially among the young. They argued that racial bias played a role in arrests and that existing laws were a waste of law enforcement resources. With the new law, punishment for possession of less than an ounce of marijuana became the equivalent of a traffic ticket.

"This new law takes away the last reason anyone would have to vote for Proposition 19," Tim Rosales, campaign manager for No on Proposition 19, said at the time.

How the Bay Area and Central Valley voted

How the San Diego area voted

The landscape of recreational marijuana laws

After Proposition 19's failure, Colorado became the first state to hold legal sales of recreational marijuana, on Jan. 1, 2014. Washington began sales in July 2014. The Oregon Legislature allowed recreational sales last year at medical marijuana dispensaries and the first retail shops began sales last month. Alaska's first marijuana retailer opened last week. Although possession of small amounts is legal in Washington, D.C., retail sales have yet to be permitted.

Law in effect Voting this year Washington, D.C. AK WA OR CO MA ME CA NV AZ

Still, California was one of the earliest in the nation to vote in favor of medical marijuana in 1996. That victory was followed by Senate Bill 420, an attempt to establish guidelines for enforcement that took effect in 2004. Statewide rules were not fully spelled out until Gov. Jerry Brown signed the Medical Marijuana Regulation and Safety Act just last year.

Section of a sample ballot from the 2016 general election. (L.A. County Registrar-Recorder/County Clerk)

Under this year’s proposition, possession would be legal for people 21 and older and marijuana would be taxed when cultivated and sold. People serving sentences for offenses that would be considered legal under the new law become eligible for resentencing. Even those no longer incarcerated could request to have their criminal records changed.

The attitude toward recreational marijuana in California has changed dramatically since 2010. Public opinion has flipped. According to the latest USC Dornsife/Los Angeles Times poll, support for Proposition 19 is leading 58% to 37%.

Would you vote yes to support or no to oppose Proposition 64?

0 1 0 20 30 40 50 60 58% Yes 37% No Note: The poll among registered California voters was conducted Oct. 22-30. The question was answered by 1,500 voters and has a margin of error of plus or minus 2.3 percentage points.

The proposition has also garnered more support from public officials and news organizations. Lt. Gov. Gavin Newsom and former Los Angeles Mayor Antonio Villaraigosa support the measure. The Los Angeles Times and the San Diego Union-Tribune have endorsed it as well.

The California Republican Party and California Police Chiefs Assn. are among groups that have come out against the measure.

Sources: Statewide Database at U.C. Berkeley Law, California secretary of state, USC Dornsife/Los Angeles Times poll