According to a new SurveyUSA poll, 50 percent of likely voters in California say they are certain to vote yes on Proposition 19, which would legalize, regulate and tax marijuana. On the other hand, only 40 percent of likely voters said that they are are certain to vote no on Prop 19.

SurveyUSA (8/9-11)
Prop 19
Certain Yes 50%
Certain No 40%
Not Certain 10%

Support for Prop 19 has remained unchanged over the past month. When SurveyUSA polled the same question one month ago, they found the same 50 percent of likely voters certain to vote yes and 40 percent certain to vote no. Combine this with a recent poll about marijuana legalization from Field and a PPP poll on Prop 19, and it seems that there is a bare but firm majority of California voters that supports legalizing marijuana.

This new poll finds most people people certain to vote one way or another on Prop 19 and relatively few undecided. It is unusual for so many people to have already locked into a position about a ballot measure three months away from the election, but clearly Prop 19 is much higher profile and easier to understand than most initiatives.

With most voters having already made up their minds about how they plan to vote on Prop 19, and with only about 50% certain to vote yes as of today, it looks like the initiative’s success or failure will come down to turnout.

Some potentially bad news on that front for supporters of Prop 19 , however, is a Pew poll that found young voters nationwide are not strongly engaged in this election or motivated to vote. Young voters tend to be much more supportive of marijuana legalization than older voters. It remains a question whether having marijuana legalization on the ballot can motivate many young voters to get to the polls in California this November.