Marijuana policy opinions in Washington state since legalization: Would voters vote the same way?

Background: In 2012, voters in Washington state approved Initiative 502 (I-502) which legalized recreational marijuana use at the state level. This study examines the relationship between demographics, marijuana and alcohol use, and voting outcomes, as well as how these variables relate to (i) whether voters would still vote the same way (a reflection of satisfaction with the new policy) and (ii) the likelihood of using marijuana purchased from legal retail stores. Methods: The sample consists of 2,007 adult Washington state residents recruited through Random Digit Dial between January and October 2014. Bivariate tests and multivariable regressions were used for analyses. Results: Less than 5% of those who voted for marijuana legalization would change their votes, whereas 14% of those who voted against legalization would change their votes. In multivariable models controlling for demographics, substance use, and marijuana-related opinions, those who voted for legalization had half the odds of changing their votes than those who voted against it. Among past-year nonmarijuana users, almost 10% were somewhat/very likely to use marijuana if they could buy it from a legal store. Past marijuana use, the belief that adults should be allowed to grow marijuana for personal use, and the belief that marijuana is not very risky for health were all related to increased likelihood of using marijuana purchased from legal stores. Conclusion: Since November 2012, support for marijuana legalization in Washington state has increased; accounting for the proportion of voters who would change their votes suggests that I-502 would pass today with even more votes in favor.