Massachusetts, California, Oregon, Maine, and Nevada are most likely to be the next five states to legalize marijuana, based on careful analysis. In the near term, two basic things are required before a state is likely to legalize marijuana. The state needs to allow citizen ballot initiatives and have an electorate ready to embrace reform.

While the approval of marijuana legalization in Colorado and Washington State has made it easier for politicians to come out in support of legalization, as a group politicians are still well behind the rest of the country on this issue and are risk-adverse. No state currently has a legislature where anywhere near half the members have publicly endorsed marijuana legalization. Most politicians are probably going to wait to see how the federal government responds and how the regulation works in these two states before putting forward their own laws. As with medical marijuana back in the 1990′s, it is likely that more than a half dozens states will approve it at the ballot box before it is finally passed by a state legislature.

That means in the short-term almost all the action will result from initiatives but just under half all states even allow some form of citizen initiative. The next several states to legalize marijuana will most likely come from this group.

Even if a state’s law would allow citizens to put a marijuana legalization question on the ballot, it will fail unless a majority of the voters in the state support legalization. Theoretically, a legalization initiative could be put on the ballot in Utah next year, but it would be destined to fail in such a deeply conservative state.

The easiest way to approximate how much support there is for legalization in a state is to look at how liberal it is. According to Gallup, as a group “Liberals” are the most supportive of marijuana reform and “Conservatives” are among the least. It is safe to assume that the more liberal the state, the more likely it is to support marijuana reform.

Unfortunately, as you can see in this chart of the 20 states with the most Liberals, relatively few allow initiatives. Of the ones that do, the obvious top tier targets are Oregon, California and Massachusetts. Voters in Massachusetts recently overwhelmingly approved both marijuana decriminalization and medical marijuana initiatives. In addition, the vote on local advisory question indicates strong support for legalization. It is probably the most favorable place for a campaign.

In recent elections marijuana initiatives came close to winning approval in California and Oregon, but part of the problem was poorly drafted initiatives as well as funding issues. With better campaigns, better initiatives, and slightly more time for support to grow both states should be in good position in the next few election cycles

The second tier consists of Nevada and Maine. They are not as liberal as the first tier states, but they are significantly more liberal than the country as a whole. Both states were also among the earliest to approve medical marijuana at the ballot box. Maine voters approved of medical marijuana in 1999, while Maine voters approved it in 2000.

Predicting the future is impossible but if one can make reasonable assumptions based on data and previous patterns. Indications are that five states most likely to adopt marijuana legalization next are Massachusetts, California, Oregon, Maine and Nevada – in that order. These will be the top targets for national organizations working to advance the issue.

*data from Gallup about percent Liberal