From the working paper:

Politicians are much more likely to erroneously believe that their constituents are more conservative than they actually are than to erroneously believe that their constituents are more liberal than they actually are. As demonstrated by the loess curves, candidates generally overestimate the degree to which their constituents hold conservative views on these issues and by more than 10 percentage points. The preponderance of the politicians in our sample – more than three-fourths – consistently underestimate support for and overestimate opposition to these policies among their constituents. Put differently, for the typical politician to believe that these policies command majority support, it appears that public support would need to pass a threshold of close to 60%.

While they did not specifically look at opinions on marijuana legalization, I think the research is highly relevant to the marijuana reform movement.

One of the issues they found politicians constantly underestimating their constituents’ support for is same-sex marriage. Popular opinion of same-sex marriage has tended to closely mirror that of marijuana legalization. Not only has the overall level of support for both issues been similar for years but the partisan and generational crosstabs are nearly identical.

It is probably safe to assume that even in states where a majority of voters now support marijuana legalization, most of the elected representatives are either unaware of this fact or haven’t truly internalized this information. They are probably greatly underestimating the popularity of the idea.

This a serious problem for the movement as it tries to get state legislatures to adopt marijuana reform laws. Assuming the working paper’s conclusions are correct and apply to this issue, it is likely support for marijuana legalization will need to poll above 60 percent before it would stand a good chance of being adopted by a state legislature.

However, this also points to a clear opportunity for the movement. In many states, regular people no longer need to be convinced that legalization is a smart move– the issue already has majority support. The movement could make big strides by simply showing a rather small number of politicians this is really what their constituents want.

Highly coordinated constituent outreach campaigns can be very effective at causing politicians to rethink where their voters stand on an issue.