Waldman's take:

At the moment, there remains a strong incentive to support the status quo, lest you be targeted in your next race as some kind of hippie-lover. The incentives on the other side, on the other hand, are almost nil. When was the last time somebody lost a race for being too tough on drugs? The half of Americans who favor marijuana legalization are not an organized voting bloc that gets together to punish its opponents at the polls.