Marijuana will be legal in all 50 states by . . . .

Marijuana legalization has been one of the most notable law reform movements of the past two decades. In this post, I want to analyze the pace of these reforms in the hopes of formulating some (necessarily speculative) predictions about the future of the movement.

Since 1996, 21 states have legalized marijuana for medical purposes – roughly 1.15 new states per year. Of course, the rate of adoption has varied somewhat across those 18 plus years, with as many as 3 states legalizing marijuana in some years and 0 states legalizing marijuana in other years. But the pace of reform has been remarkably steady over time, notwithstanding several major “events” during this span, including: Drug Czar Barry McCaffrey’s call to all federal agencies to combat state reforms (1997); the U.S. Supreme Court’s decisions in Oakland Cannabis (2001) and Raich (2005); and the DOJ’s issuance of (non-) enforcement memos in 2009, 2010, and 2013. The following graph (using data helpfully gathered by ProCon.org) shows the number of new states legalizing medical marijuana by year since 1996:

If adoptions continue at the 1996- rate, medical marijuana would be legal in all states by 2039.

Obviously, this is a very simplistic way of predicting the future, based on simplified data (reforms vary across states, after all). A number of factors could hasten, slow, or even reverse the legalization of marijuana going forward. For example, legalization may come more slowly in the 29 remaining states, because voters in those states have comparatively restricted access to direct lawmaking procedures. (More than half the 21 states that have legalized medical marijuana so far have done so via voter initiative, but only 11 of the 29 remaining states appear to have comparable initiative procedures.)  On the other hand, public support for legalization of recreational marijuana is growing (support for medical marijuana has been high for quite some time), potentially defusing one of the key arguments against legalization of medical marijuana – namely, that supplies of it will be diverted into the recreational market. But I’ll go out on a limb and say that by 2039, marijuana will be legal (for purposes of state law) in every state. If I’m wrong, I’ll even buy Doug Berman and Alex Kreit a Big Gulp of Coke. If THAT’s still legal, of course.