These numbers suggest that people who only slightly supported legalization last year have changed their minds, and that people who slightly opposed legalization now feel more strongly about it. They could augur difficulties for marijuana legalization measures on the ballot this year in Alaska and Oregon. An August PPP poll found Alaska voters closely divided on the marijuana question, with 44 percent in favor of legalization and 49 percent opposed. A June SurveyUSA poll found more robust support for legalization in Oregon, at 51 to 41.
An October 2013 Gallup poll found strong support for marijuana legalization nationally, with 58 percent in favor and 39 percent opposed. The PRRI and Gallup numbers are not directly comparable, since the questions were worded differently in each survey. Moreover, survey responses on marijuana legalization tend to be highly sensitive to particular question wording.
Still, the year-over-year drop within this one poll is significant and well outside the poll's 1.8 point margin of error. If other surveys show similar findings, it could mean that Americans generally don't like the news coming out of Colorado and Washington - even if that news has been largely positive.