A new A.P. poll finds that the number of Americans who oppose marijuana legalization has fallen dramatically in the last few years. In a survey completed last week, 29 percent of respondents said they opposed "legalizing the possession of small amounts of marijuana for personal use," compared to 55 percent in 2010. A.P. notes that the 2010 survey was conducted by phone, while the new one was conducted online, a method that tends to boost neutral responses. The share of respondents who said they "neither favor nor oppose" legalizing marijuana tripled between 2010 and 2013, while the percentage favoring legalization rose only slightly. Still, the A.P. numbers are consistent with other surveys in finding increased receptiveness to repealing marijuana prohibition.

The most dramatic of those results was Gallup's finding in October that 58 percent of Americans think "the use of marijuana should be made legal." That was the highest level of support for legalization ever found by a Gallup poll. But like the question used by A.P., Gallup's wording suggests a relatively narrow reform that does not necessarily include legalizing commercial production and distribution, as Colorado and Washington have done. Whether that policy receives majority support depends on how the question is worded. In the most recent Reason-Rupe Public Opinion Survey, for example, 49 percent of respondents said yes to "legalizing marijuana," while 47 percent said no. But in a Reason-Rupe poll conducted in January, 53 percent of respondents said "the government should treat marijuana the same as alcohol."

Similarly, 56 percent of respondents in a 2010 A.P.-CNBC poll said regulations for marijuana should be either the same as or less strict than regulations for alcohol. A 2011 YouGov/Economist poll found a similar level of support (58 percent) for treating marijuana like alcohol. Meanwhile, just 36 percent of the respondents in this month's A.P. survey were prepared to voice support merely for "legalizing the possession of small amounts of marijuana for personal use."

What's going on here? Looking at the differences between the A.P. and Gallup results, it may be that "possession" (which is, after all, currently a crime) triggers more negative associations than "use" (which is not in itself defined as a crime, although it obviously entails possession). And why does "legalizing marijuana," which could mean anything from not arresting users to completely repealing prohibition, get less support than treating marijuana like alcohol, which necessarily means legalizing production and sale as well as possession? Likening marijuana to alcohol evokes a familiar legal model and suggests a moral equivalency that is hard to deny. That was the approach that reformers took in Colorado and Washington, and legalization got about 55 percent of the vote in both states.

[Thanks to Richard Cowan for the tip.]