Calif. 'Frankenfood' Bill in Death Spiral After Ad War Opponents spend $46M in GMO labeling battle By Matt Cantor, Newser User Posted Nov 5, 2012 6:27 AM CST Updated Nov 5, 2012 7:40 AM CST 42 comments Comments This Sept. 30, 2002 file photo shows labeling advertising no genetically engineered ingredients. (AP Photo/Paul Sakuma, File) (Newser) – At first, advocates for California's Proposition 37 seemed to be skipping off to victory—but with the vote approaching, it now appears that opponents have engineered a stunning turnaround. Monsanto, DuPont, and Pepsi have spent some $46 million against the measure, which would require the labeling of genetically-modified food. In a raft of television ads, opponents argue that it would hike family grocery bills by $400 a year while hurting farmers. And the ads seem to have worked: A month ago, some two-thirds of likely voters supported the measure; now, just 39% support it, while 51% oppose it. The "No on 37" campaign is among California's best-funded ballot battles ever, Reuters notes. Opponents have spent about six times what advocates have spent. It's been compared to the fight against a proposed tobacco tax measure earlier this year, which was defeated despite initially having 70% support. An anti-smoking activist says in both cases, ads weren't "arguing with the premise of the initiatives, but rather making picky criticisms of the details of the initiatives."