In October 2010, with a quixotic marijuana initiative leading in California polls, U.S. Attorney General Eric Holder answered an urgent letter from retired heads of the federal Drug Enforcement Administration.
"Let me state clearly that the Department of Justice strongly opposes Proposition 19," Holder wrote, declaring he would "vigorously enforce" federal law if California voters passed the measure, which would have legalized recreational marijuana use for adults over 21 and allowed retail sales of pot.
This year, Holder notably declined to respond as the retired DEA administrators sent him another anxious letter expressing opposition to marijuana legalization efforts. This time, voters in two states, Washington and Colorado, voted 55 percent to 45 percent to legalize marijuana beyond medical use, upping the stakes in America's marijuana debate.
California, which passed America's first medical marijuana initiative in 1996 and pushed the envelope on legalization in 2010, has become an also-ran in the discussion. The state also lags in regulation of medical cannibis.
"It feels like you guys are still going through the awkward step of adolescence, and Colorado and Washington have gone on to the next step," said Sam Kamin, a professor at the University of Denver's Sturm College of Law who researches marijuana policy.
In California, where Holder's letter was widely publicized and flipped the polls as Proposition 19 went down to defeat, marijuana advocates hope successful legalization votes elsewhere will at least persuade the Legislature to regulate the state's existing medical marijuana industry, which operates in an amorphous legal haze.
"This is called a game-changer," said Ellen Komp, California deputy director for the National Organization for the Reform of Marijuana Laws. The group backed failed legislation this year to license California medical marijuana dispensaries and growers in hopes that stricter state oversight would help repel an ongoing federal crackdown.
"No one thought we were going to get a full legalization measure anywhere Now everyone is waiting to see what the federal response will be in Colorado and Washington."
Don Duncan is the California director of Americans for Safe Access, an advocacy group for medical marijuana users. He said the developments in Colorado and Washington may make it easier to persuade California lawmakers – who have been wary of being seen as champions for marijuana stores – to set rules for the state's medical cannabis industry when a new bill is introduced in January.
"I'm guardedly optimistic this changes the landscape in our favor," Duncan said. "We're not the most radical people at the table anymore."
The four U.S. attorneys in California have been systematically cracking down on the state's medical marijuana businesses, contending that many are cash-reaping enterprises profiteering in violation of both the federal Controlled Substances Act and state medical marijuana laws, which require pot operations to be nonprofit.
In an interview this week, Sacramento U.S. Attorney Benjamin Wagner said the votes in Washington and Colorado won't have any immediate impact on federal enforcement efforts in California.
"In the short term, I don't think it's going to have much effect on what we're doing here in California," Wagner said. "We're not really in the business of trying to shape state legislation or state policy. We're in the business of enforcing federal law, and so long as conditions in California stay the same, our enforcement efforts are going to be pretty much the same."
Federal officials have said little so far about how they will respond to legalization of recreational marijuana sales and use in Colorado and Washington.
Compared with California – where Wagner has called the medical marijuana industry an "unregulated free-for-all" – federal crackdowns on medical marijuana outlets in Colorado have been considerably more restrained. That is credited in large part to Colorado's efforts to strictly regulate its medical marijuana market.
Medical marijuana workers in Colorado must be licensed by the state. All transactions and shipments are videotaped, and a state policing agency – the Colorado Medical Marijuana Enforcement Bureau – oversees the industry.
Kamin, the University of Denver professor, said the perceived success of Colorado's medical marijuana regulatory oversight made it easier for voters there to sanction the use of marijuana as a purely pleasurable pursuit for adults.
"Everything is already in place with regulations we can cut and paste. And we know it works," Kamin said.
Analysts say voter demographics also played a role. Unlike in California, where Proposition 19 lost by 53.5 percent to 46.5 percent in 2010, the Colorado and Washington measures played out during a presidential election year with a more diverse electorate, including a strong turnout among young voters.
Colorado was a presidential swing state – a factor advocates suggest may have dissuaded President Barack Obama's attorney general, Holder, from weighing in this time around.
"I think it's safe to say that there were politics involved," said Brian Vicente, co-director of the Amendment 64 campaign. "Marijuana is demonstrably more popular in Colorado than President Obama."
The president won Colorado – but the pot measure got a greater share of the state vote.
Marijuana advocates in Washington and Colorado said they learned from the defeat of California's Proposition 19. The two victorious measures added provisions for state regulation of recreational sales – and the first-ever standards for testing drivers for pot impairment.
"This is a maturation of the discussion on marijuana," said Allison Holcomb, director of the New Approach Washington campaign that passed the legalization measure. "It changed the dynamic of the conversation altogether."