Who votes for marijuana reform? And some predictions

Since this is a bit wonk-ish, I decided to put my predictions up front. The explanation (and some cool graphs) are below.

This is what I expect to see from the House of Representatives in the next two years on marijuana issues:

81% of votes in support of medical marijuana
54% of votes in support of marijuana decrim
32% of votes in support of marijuana legalization

According to this, decriminalization has a better than even chance of passing the house. I don't know what the margin of error is on these, so I can't say exactly how high the odds are, but higher than 50%, at least. (I'm sure my newly elected state representative -- drug warrior Delmar Burridge, from Keene -- will be upset about that!)

Legalization garnered much less support than decriminalization, and likely won't pass this session. But it's nearly a certainty that New Hampshire will have medical marijuana within the next two years, since Maggie Hassan has vowed not to veto it.

To get a better idea of how marijuana-related issues are decided in the State House, I used the W-NOMINATE data from the 2011-2012 legislative session.

As usual, the x-axis measures the stereotypical left/right political spectrum, with Republicans on the right and Democrats on the left. It's not so clear what the y-axis measures.

Here are the results of roll calls on three different bills, SB409 (medical marijuana), HB1526 (marijuana decrim), and HB1705 (marijuana legalization). Click to enlarge.

SB409

(medical marijuana)

Yea = for, Nay = against

HB1526

(decriminalization)

Yea = for, Nay = against

HB1705

(legalization)

Nay = for, Yea = against

NOMINATE doesn't pick up these issues very well, and the cutting lines (the black line that goes through the graph -- it's supposed to separate the Yeas from the Nays) aren't so useful. But it does seem that legislators on the top of the graph are more likely to support reforms, and those on the bottom are more likely to oppose them.

After a few days of voting in the new session, I can get new NOMINATE data to help inform predictions, but in the meantime, predictions based on party should work well enough.

A few caveats-- many things could change these results. The wording of a particular bill could push legislators one way or another. The Speaker of the House may try to sway legislators in her preferred direction. There may be an upward or downward shift in the NOMINATE scores of the new legislators. A lot of Democrats may stay home one day, or any of a thousand other events may occur that alter the outcomes.

In any case, I counted the number of Yeas and Nays in each party, and calculated the probability of a random legislator from each party voting in support of each issue. The most recent estimate I saw of each party's representation in the house comes from Steve Vaillancourt. He expects 223 Democrats and 177 Republicans. The results are up top.