If you're looking for a one-sentence explanation of why "yes" won on the 66/67 votes yesterday, well, there isn't one. There are lots of individual factors, though. The structuring of the taxes involved (while far from perfect) were such as to appeal to a clear majority of voters. It helped that the yes side wasn't outspent by no (which might have been the case - in fact the two sides weren't that terribly far apart).
Blue Oregon's Kari Chisholm has drawn a common line through the votes for Oregon taxes, Massachusetts Senate and New Jersey governor - all responses against a wealthy or insider elite.
And there was something else: The massive ground game put on the yes people, especially in the last week. The margin in Multnomah County (Portland/Gresham) in favor of the issues was so large that it nearly equalled the statewide margin in favor, and Multnomah balloting was sluggish as recently as late last week. Then volunteers pulled in the votes by the tens of thousands.
Another Blue Oregon writer, T.A. Barnhart, pointed out (on a Facebook comment today) that the turnout level (upward of 50%) was not such as ordinarily might help this kind of ballot issue. But: "the tv ads may have been good (i only saw a few) but it was the ground game that won this. a lot of that money supported that: the Activate phone system, flyers, staff, offices, etc. if volunteers by the thousands had not busted ass for weeks, no tv ad would have saved us. and it's awesome because it shows us how we win progressive victories. Howard Dean gets it; Rahm Emmanuel does not. hence the problems Obama faces for his choice in advisors."
Lots of food for thought here.