The stakes couldn’t be higher.

On Tuesday, California voters have a chance to make marijuana legal in the world’s sixth-largest economy.

If they do, many advocates believe that the end of federal cannabis prohibition in the United States could soon follow.

Polls now consistently show that California’s Proposition 64 is poised to pass, but just six years ago voters in the Golden State rejected a ballot measure to legalize marijuana.

What has changed since 2010?

The most important thing that has happened since the earlier initiative, Proposition 19, failed with 46.5 percent of the vote is that other states have gone ahead and ended their own prohibition laws. Four of them, in fact: Alaska, Colorado, Oregon and Washington State. Plus the nation’s capital, Washington, D.C.

The implementation of these laws has proved largely successful, with jobs being created, tax revenue being generated and arrests dropping, all while youth marijuana use hasn’t risen.

As a result, other states are eager to get on board, and joining California in considering legalization measures this year are Arizona, Maine, Massachusetts and Nevada. Surveys show that all five have a good shot of passing.

In California specifically, a comparison of 2010 and 2016 polls by the state’s prestigious Field Research Corporation shows just how dramatically support for legalizing cannabis has risen across every demographic:

Over the past six years, support for ending prohibition nearly doubled among Latinos and tripled among Asian Americans. It jumped 15 points among African Americans and a whopping 29 points among those aged 40-49. There’s no category in the survey that backs legalization less now than it did in 2010.

Elected Officials On Board This Time

In addition to — perhaps as a result of — the attitude shift in voters, more of the state’s elites are adding their voices in support of legalization this year, whereas very few did so during the 2010 campaign.

Major daily newspaper editorial boards like those of the Los Angeles Times and the San Francisco Chronicle endorsed this year’s measure, while they opposed the earlier Proposition 19.

On Friday, Congresswoman Nancy Pelosi, who leads Democrats in the U.S. House of Representatives, said that she’s voting in favor of Proposition 64. She didn’t back legalization in 2010. Ditto for Antonio Villaraigosa and Willie Brown, the still-prominent former mayors of Los Angeles and San Francisco.

In 2010, Gavin Newsom, then the mayor of San Francisco, couldn’t bring himself to even issue a public endorsement of what could have been the first successful statewide measure to legalize marijuana. Now, as the state’s Lieutenant Governor, he personally appointed a blue ribbon commission whose findings directly informed the drafting of Proposition 64 itself. He’s since served as one of the measure’s chief spokespersons, clearly seeing the popular issue as a benefit to his already-announced run for governor in 2018.

Barbara Boxer, one of California’s two U.S. senators said that she’s “leaning in favor” of this year’s measure, while she opposed the one six years ago.

Kamala Harris, running to replace the retiring Boxer in the Senate, says that her current job as state attorney general prevents her from taking an official position on the measure, but she predicted in a debate last month that voters will approve it. That’s a big change from just two years ago, when she literally laughed off a reporter’s marijuana question.

And while Gov. Jerry Brown has been quick to trash the idea of legalizing marijuana whenever asked about it in the past, he told the Chronicle’s editorial board in a meeting recently that he is “mulling” whether to reverse his position and vote for Proposition 64.

California’s Impact on Federal Marijuana Prohibition

If the measure does pass, it could force Congress and the next president to seriously consider scaling back federal prohibition laws

President Obama said in an interview last week that federal criminalization and enforcement efforts are “not gonna be tenable” if marijuana becomes legal across the entire West coast, as well as other parts of the U.S., on November 8.

“The good news is is that after this referenda, to some degree it’s gonna call the question,” he said, “because if in fact it passed in all these states, you now have about a fifth of the country that’s operating under one set of laws, and four-fifths in another.”

Practical policy implications aside, the impact of California and other states vote to legalize marijuana on Tuesday could have enough of a political effect to force Congress to act.

A Mariuana.com analysis of recent U.S. House votes on marijuana amendments found that the several dozen more federal lawmakers who could represent states with legal marijuana after Tuesday would be more than enough to enact far-reaching reforms.

For example, an amendment to prevent the Department of Justice and Drug Enforcement Administration (DEA) from interfering with marijuana laws failed by just nine votes last year. California alone is represented by 53 House members.

Democratic presidential candidate Hillary Clinton and her Republican opponent Donald Trump have both pledged to respect the right of states to implement their own marijuana laws without federal interference, and would likely not stand in the way of cannabis policy reforms proposed by Congress.

Proposition 64 Details

Beyond the federal policy implications, Proposition 64 will have a big impact on Californians themselves. If passed, it will become legal for adults over 21 years of age to possess, transport, purchase, consume and share up to one ounce of marijuana and eight grams of marijuana concentrates. They could also grow up to six cannabis plants at home.

The measure would create a process to allow people with prior marijuana offenses to have their records dismissed.

A new Bureau of Marijuana Control would be responsible for licensing cannabis stores and commercial cultivators.

A 15 percent excise tax would be imposed on retail sales, which, together with separate taxes on commercial growers, are estimated to generate more than $1 billion in new tax revenue each year. The money would support education, drug treatment, environmental cleanup and other services.

Proposition 64 would not affect existing rights for medical marijuana patients.

Polls have consistently shown the measure leading, with the most recent Field Research Corporation poll finding 57 percent of likely voters in support.