Now, more jurisdictions are taking up, or at least considering taking up the issue.
In Maine Monday, Portland City Council planned a public hearing to discuss a citizen-proposed measure legalizing possession of up to 2.5 ounces of marijuana for those 21 and older. After the meeting, the city council will decide whether to adopt the measure, send a referendum to voters or write an alternative proposal alongside the citizen measure.
Proponents gathered more than twice the 1,500 signatures required to get the proposal, which would prohibit smoking pot in public spaces such as schools or public parks, and allow landlords to prohibit it in their apartments, on this year's ballot.
Maine law allows medical marijuana, and has already decriminalized its use, but possession of a small amount still carries a maximum fine of $600. A state-wide referendum on legalization is expected in 2014.
In the nation's capital, a D.C. councilman introduced a bill Wednesday to decriminalize possession in the District.
Councilman Tommy Wells unveiled legislation to drop the penalty for carrying less than an ounce of marijuana to $100, down from $1,000 or a six-month prison stint.
Wells's legislation also stipulates minors attend a drug awareness program and complete community service.
An American Civil Liberties Union report in June found the District bears the country's highest arrest rate per capita in the country for marijuana possession-related arrests, at three times the national average. Those are three times more likely to involve an African American than a caucasian.
Moves toward decriminalization and legalization receive broad support in D.C., with 75 percent of residents saying they support decriminalization in small amounts and 63 percent say they're in favor of legalization, according to an April PPP poll.
And in California, which rejected a 2010 measure for legalization, already has medical marijuana and decriminalization laws on the books.
But the legalization effort is likely to make another ballot appearance in 2016, with the backing of some of the state's wealthiest citizens. Silicon Valley's entrepreneurs and the billionaires behind some of the world's most successful tech companies are expected to back the effort.
Coalition for Cannabis Policy Reform chairwoman Dale Sky Jones said 2010's Proposition 19 failed largely because of fundraising shortfalls.
Liberal billionaire George Soros helped back that measure and Prop. 215, the successful 1996 medical marijuana bill, will probably help again, and Progressive insurance chief Peter Lewis are still "engaged" Jones said.
But it's Silicon Valley that gives her the most optimism.
Bay-area entrepreneurs such as Facebook founders Sean Parker and Dustin Moskovitz, who both put substantial funds into the 2010 effort have "network of friends" to tap into, Jones said. "There's money to burn in those industries."