The 2012 Marijuana Ballot Measures: Every State and Local Result

By James Buddsey · Updated October 30, 2026

On November 6, 2012, voters in six states decided statewide marijuana measures: Colorado and Washington legalized adult use, Massachusetts approved medical marijuana, Montana kept a restrictive medical law, and Oregon and Arkansas said no. Voters in several Michigan cities also passed local reforms. It was the first election in which any state voted to legalize marijuana for adults, and it set the pattern of ballot-driven legalization that followed.

What Happened

The statewide results:

Vote counts are from the official tallies cited in the Wikipedia articles on Amendment 64, Initiative 502 (Washington Secretary of State), Question 3, Measure 80 (Oregon Elections Division), the Montana ballot measures list (via Ballotpedia) and Cannabis in Arkansas. Percentages are of yes and no votes cast.

Colorado Amendment 64 and Washington Initiative 502

Colorado’s Amendment 64, the Regulate Marijuana Like Alcohol Act, passed with 1,383,140 votes (55.32%) to 1,116,894 (44.68%), according to state results. It amended the Colorado Constitution to let adults 21 and older possess up to 1 ounce and grow up to six plants, and directed the state to license and regulate stores.

Washington’s Initiative 502 passed with 1,724,209 votes (55.70%) to 1,371,235 (44.30%), certified on December 5, 2012 (Washington Secretary of State). It legalized possession of 1 ounce of usable marijuana, 16 ounces of solid infused products and 72 ounces of infused liquids for adults 21 and older, set a 5 ng/mL THC blood limit for driving, and created a state-licensed system of growers, processors and stores with a 25% excise tax at each level. It did not allow home growing.

The campaigns. Neither win was a sure thing. A Public Policy Polling survey on October 23, 2012, showed Amendment 64 ahead 53% to 46%. In Washington, the campaign split the cannabis community itself. Medical marijuana activist Steve Sarich led opposition to I-502, and Seattle Hempfest chose not to endorse it; its director, Vivian McPeak, co-signed a letter opposing the DUI language, which many patients feared would make them guilty of impaired driving even when sober (I-502 history). Gov. Chris Gregoire and both 2012 candidates for governor also opposed the measure.

Federal pressure was open. On September 7, 2012, nine former heads of the Drug Enforcement Administration, including John Bartels and Karen Tandy, wrote to Attorney General Eric Holder urging him to publicly oppose Amendment 64, I-502 and Oregon’s Measure 80, NORML and Reuters reported. Holder’s office declined to comment. Washington’s state fiscal office had estimated the initiative could raise more than $560 million in its first full year.

From vote to stores. The laws took hold quickly. Washington’s possession rules took effect December 6, 2012, when crowds gathered near the Space Needle after midnight (Reuters). King and Pierce county prosecutors dropped pending misdemeanor possession cases. In Colorado, Gov. John Hickenlooper formally added Amendment 64 to the constitution on December 10, 2012, and created a task force to write the rules; it issued 58 recommendations in March 2013. Denver’s City Council adopted its retail ordinance on September 16, 2013 (Denver Post), and Colorado voters approved Proposition AA’s marijuana taxes that November.

The federal answer came on August 29, 2013, when Deputy Attorney General James Cole issued a memo saying the Justice Department would not sue to block the states and would focus on eight priorities, such as sales to minors and diversion across state lines (New York Times). Our article on the Ogden and Cole memos covers that policy in full.

Colorado’s first stores opened on January 1, 2014 (New York Times). Washington issued its first retail licenses on July 7, 2014, and stores opened the following day (KPLU). Washington later replaced its three-tier tax with a single 37% retail excise tax and folded its unregulated medical dispensaries into the licensed system by July 2016. In 2015, Nebraska and Oklahoma asked the U.S. Supreme Court to strike down Colorado’s law; the Court declined on March 21, 2016.

Massachusetts Question 3

Massachusetts became a medical marijuana state with the largest margin of the night. Question 3 allowed qualifying patients to obtain a 60-day supply and created nonprofit treatment centers, with limited home growing for patients who could not reach one.

Montana IR-124

Montana’s vote was the reverse of a reform measure. In 2011 the Legislature replaced the 2004 voter-approved medical marijuana law with Senate Bill 423, which sharply limited providers. Opponents forced the law onto the ballot as a referendum, but a “yes” vote upheld it, and 57 percent voted yes. The story of SB 423 and the federal raids around it is told in our article on Montana SB 423.

Oregon Measure 80

The Oregon Cannabis Tax Act would have allowed personal growing and use without a license and created a commission to regulate commercial cultivation and sales. It lost by about 112,000 votes, the only legalization measure on the 2012 ballot to fail.

Arkansas Issue 5

The Arkansas Medical Marijuana Act would have allowed nonprofit organizations to grow and sell medical cannabis and let patients living more than five miles from a dispensary grow a small number of plants. It came within about three points of passing in a conservative Southern state.

Local Measures

Michigan cities produced most of the local wins. According to NORML’s tally:

• Detroit (65%): Proposal M removed city criminal penalties for adults 21 and older possessing up to an ounce on private property.
• Flint (54%): removed city criminal penalties for possession of up to an ounce on private property by people 19 and older.
• Grand Rapids (60%): Proposal 2 let police issue a civil citation with a $25 fine and no criminal record to first-time offenders.
• Ypsilanti (74%): made marijuana possession the city’s lowest law enforcement priority.

Kalamazoo voters also approved a proposal to allow medical marijuana dispensaries despite state court rulings against them, Michigan Public reported. These measures changed city ordinances only. State and federal law still applied, and Flint’s city attorney called that city’s measure “symbolic.”

Why It Mattered

Before 2012, every statewide legalization measure had failed, including California’s Proposition 19 in 2010. The 2012 results showed that a carefully drafted, tax-and-regulate measure could win a majority in a presidential election year. Oregon’s loss also became a lesson: its measure was broader and less tightly regulated than Colorado’s or Washington’s, and the measure Oregon passed two years later was much narrower.

What Happened Next

• Oregon legalized two years later with Measure 91 in 2014.
• Massachusetts voters legalized adult use with Question 4 in 2016.
• Arkansas approved medical marijuana with Issue 6 on November 8, 2016.
• Montana voters loosened the medical program with Initiative 182 in 2016 and legalized adult use with Initiative 190 in 2020.
• Michigan legalized adult use statewide in 2018, replacing the patchwork of city ordinances.
• Colorado and Washington opened the first adult-use stores in 2014. Colorado’s results are tracked in our Colorado sales by year page.

Where It Stands in 2026

Of the six states that voted in 2012, all but Arkansas now allow adult-use cannabis, and Arkansas has a medical program. Current rules are in our state guides for Colorado, Washington, Oregon, Massachusetts, Montana, Arkansas and Michigan, and on our cannabis laws by state page. Marijuana remains illegal under federal law for adult use; see our federal laws page.

2012 Marijuana Ballot Measures FAQ

Originally reported by The Weed Street Journal; rewritten and updated in October 2026 with what happened next.