A prediction: I expect that Prop 37 will pass, and as a result, almost all manufacturers will add a label stating "in order to comply with California law, this food may contain genetically engineered ingredients", and we can add yet another completely useless label to things. Kind of like the label on every apartment building with a parking garage: "this building may contain known carcinogens". You could have a garage with oil drips or a ceiling/ flooring full of asbestos, and the label is the same, despite the common sense that the two risks are not equivalent.
What makes sense (to one person, a given voter) doesn't always make sense (to the corpus). You know that this law is going to run afoul of interstate commerce laws, putting millions into the hands of lawyers and doing nothing to improve the safety of food, right? Labeling something when the threat is unknown is kind of like warning kids who masturbate that they'll go blind. Eventually, the truth will out, and who pays in advance for the backlash? You can't create a boogeyman just to influence people's behavior in a way that you want. (You can argue the boogeyman is real, but the realness of the boogeyman is immaterial- people still smoke knowing full well the boogeyman has a knife on their lungs)
Needless to say, I'm advocating no on 37. That's no surprise- I would willingly eat GMO especially if it were labeled. But for those of you who would vote yes, take a minute to think about what this law will accomplish. For those of you who are diehard organic consumers, your behavior won't change, but it is very likely the amount of paperwork that your organic farmer will need to produce to demonstrate that their crops are not contaminated with GMOs will likely increase the burden on them, and the cost of doing exactly what you do now will go up. Things like granulated sugar, which are ~100% purified and contain next to nothing of the original plant except sugar, might get labeled when the health threat is nonexistent. The larger manufacturing companies will redesign their packaging to include a boilerplate disclaimer like the one cited above, and it is totally unlikely that anyone will notice a difference or care. Are you really less likely to buy a box of cheerios that has a label like the one above on it? Even though the product inside is completely identical, from the same lot, to the one pre-Prop-37?
Current non-GMO products proudly advertise this fact. Does it actually help your purchasing decisions, or do you buy what you buy because of your baked-in biases either for or against GMO products? Cui bono?
Monsanto may be evil, but you have no idea why. Really, you don't. Monsanto, Syngenta, and DuPont/Pioneer don't want to kill their customers, or give you cancer or other diseases. If you believe they are evil just to make a buck, you've missed out on the problem. Vigilance is difficult and expensive, and most companies are evil not because of a desire to make money, but a momentary lapse of vigilance due to tired employees rubber-stamping documents. GMO or nonGMO, that same "tired truck driver" (for lack of a better analogy) is heading the wrong way on your side of the road. What's needed is more investment in caretakers, more jobs for people who can innovate ways of keeping better watch, and an improved baseline of minimal rights for all so that we have fewer people working 3 jobs to make ends meet. Yes, that means some slackers will suck the tits of mommy welfare- but I'd rather have them home in bed, than on their third back to back shift of quality control trying to make ends meet.
What will more regulation in this regard do? Increase the workload of an already exhausted farmer. (On greater than half of farms, at least one family member needs to work off the farm to supply enough income to the household to not be in poverty. Off farm income is ~90% of farm household income. http://www.sfgate.com/food/article/Fond-memories-of-Soul-Food-Farm-3923428.php#page-2 . Don't kid yourself, farming sucks. ) They will have to face tougher choices about where to bring their products to market, leading to boom-bust pricing as the demand for each type of product varies. Fragmented markets cost more.
One of the biggest problems with artisan foods is that the market is small, by design, and produce varies sufficiently that it is not useful to larger manufacturers who need to provide a uniform product to consumers. Irrespective of taste, would you buy a spaghetti sauce that is sometimes yellow, sometimes green, and sometimes brown? (I would, because I eat with my mouth, not my eyes.) Red spaghetti sauce sells, has been demonstrated again and again in taste test trials, and "home-made", while delicious, is more expensive and not always a uniform color. Put two bottles of different lots next to one another, and the customer is going to think one of them is "spoiled". All that, and pay more for it too?
I know why the South votes Republican. The lower-middle-class mom pops a jar of Ragu, and can hear a distant sneer of a wealthy white liberal arguing that if they had made that sauce home-made, it would be cheaper and healthier, not made with transgenic corn syrup. Props to Jamie Oliver for trying to feed kids real foods, and I think in most cases people have good intentions. But for most, the good intentions and well meaning of evolution-toting, whole-food eating liberals just sounds like disrespect and paternalism. Labeling the food that they eat and "know" to be nutritious (if not entirely healthy) with a big red embroidered "GMO" then doesn't inform, it just sets people in their heels a little deeper.
Sure, there are a marginal few who will find utility in the label. But how stupid do you think people are, that they don't know that what they're eating contains GMO corn syrup? What's needed is to treat people like adults- no paternalism, no watchdoggery. "You can have aid, but only by my rules." Yes, if healthcare is free, if the minimum wage is doled out to all, there will be welfare parasites. Or, that poor kid or overworked adult might have just enough of a safety net to become an entrepeneur. Let people be what they want to be, and their desire to shake boredom might express itself in a myriad of socially useful ways.
I'm not arguing against more real testing- if glyphosate is potentially harmful, mandate maximum tolerable levels in finished product. If BT-Toxin is harmful, test for it. But a broad label of "GMO" is preaching to the (typically wealthy) choir; with no real health assistance to those who would actually benefit from it. If it's harmful, ban it outright, otherwise you're just politicking