[5] Initiative 502 defined and legalized small amounts of marijuana-related products for adults 21 and over, taxes them and designates the revenue for healthcare and substance-abuse prevention and education.

[8] The initiative legalized use of marijuana products for adults 21 and over and focus law enforcement resources on DUI prosecution as well as violent and property crimes.

[9] February 2011 analysis of the similar Washington House Bill 1550 estimated annual state and county law-enforcement savings of approximately $22 million.

[10][11] OFM's final, official analysis did not include law-enforcement savings, but estimated five-year revenues at approximately $1.9 billion from an assumed retail price of $12 per gram.

[15] Part V on "driving under the influence of marijuana" sets a per se DUI limit of "delta-9" THC levels at greater than or equal to 5 nanograms per milliliter of blood (5 ng/mL).

[20] Many groups which might traditionally be expected to take a stance on the issue have been silent, including business, education, law-enforcement, and drug treatment organizations.

[22] Eastern Washington's The Spokesman-Review endorsed I-502 from December 2011 as part of a broader call for legalization and federal reclassification of cannabis under the 1970 Controlled Substances Act.

[23] Other supporters include a variety of current legislators, organizations, former judges, law enforcement personnel, prosecutors and elected officials such as Jolene Unsoeld.

[28] Noting the disproportionate impact of marijuana arrests and incarceration on families and racial minorities, the Children's Alliance,[29] NAACP and various African-American pastors have also endorsed I-502.

[40] In July 2012, major donations of financial support were given by the Drug Policy Alliance, Peter Lewis of Progressive Insurance and the American Civil Liberties Union.

Ethan Nadelmann, founder and Executive Director of the Drug Policy Alliance at the time, said in a 2015 speech:"It was a chance to pop a hole in prohibition nationally.

And the situation presented itself: if I put up about a third of the money or so for Washington state, not withstanding my reservations, that would leverage Peter Lewis and the in-state donors and enable a campaign of five or six million dollars to win that thing.

I'm going to put that money in there because...we could pop a hole in prohibition because that was going to resonate across the country, lay the ground work for California and other states and have an even international impact.

"[42]Newspapers endorsing I-502 in the weeks immediately prior to the election include The Seattle Times,[43] The Spokesman-Review,[44] The Columbian,[45] The Olympian,[46] and The Wenatchee World.

[62] Thurston County Sheriff John Snaza said Asian and motorcycle gangs currently control "marijuana distribution and sales" and that the initiative would likely lead to more traffic fatalities and organized crime.

[64][65] Both major candidates for governor in the 2012 election also went on record in opposition, with Jay Inslee following Rob McKenna, both citing concerns for users of medical cannabis.

[69] On July 31, 2012, Sensible Washington announced its intent to "actually repeal prohibition" with a new Initiative drive in 2013, regardless of I-502's election outcome, noting in its press release that cannabis will remain a Schedule I drug under I-502, "which we're not comfortable with and will work towards correcting.

[89] Former US president Jimmy Carter referred to 502 and Colorado Amendment 64 in restating his decades-long support for decriminalization and legalization, to "let the American people see" how well it works.

[90] In his first interview on the subject after passage, President Barack Obama said that addressing this issue was not a high priority at this point, that international treaty obligations came into play, but that there were "bigger fish to fry.

[96] Some state legislators are reportedly moving to "slow down" this rule-making process[97] and national opponents Kevin Sabet and Patrick J. Kennedy have started Project SAM to promote what they call "smart approaches to marijuana.