There are good reasons to think the polls could either be overestimating or underestimating Proposition 19’s support. In spite of the recent trends against Proposition 19, therefore, I would be inclined to take the recent polling at face value, which suggests that the measure has about even odds of passing.
I sure hope that's true. Today's LA Times poll, which is not in Nate's analysis, shows a real shift toward opposition, with the initiative now trailing by 12 points. It could be an outlier, or a harbinger.