And now Vermonters' grocery selection has been cut in half.
Because it's cheaper for major producers to simply forget about the Vermont market.
This only works when big states do it. My car meets California emissions standards even though I didn't buy it in California, don't live in California now and have never driven it anywhere near California. Why? Because when you've got a market of 50M people, you can get corporations to do what you want to an extent. Vermont doesn't have that kind of leverage, and neither does any other state besides probably Texas (but they prefer to use their clout to make everyone else read school textbooks vetted by Christian fundamentalists).
You make some good points about the limited influence of any individual state, but I highly doubt it's in any food suppliers' best interest to just ignore an entire state, no matter how small.
Anyways, based on my limited knowledge of this topic, I'm gonna say I'm pro-labeling, because it doesn't like all that much of a hassle. The label should just say which ingredients were genetically modified. Frankly I think the label should be specific about what the intent of the modification was. I don't think it's "anti-science" for people to know what products contain ingredients that might have been exposed to more pesticides.