I've seen the relevant corporate farms in Kauai, which grow genetically-modified seeds. Pretty fields in a pretty place.
But the majority of residents of Kauai aren't especially happy about them. Both due to the GE portion of genetically-engineered plants as well as do the use of pesticides on the field.
So the County Council passes an ordinance that makes it a much bigger hassle to use pesticides, and that requires warnings to workers and the community. The mayor vetoes the proposed ordinance, even though he's sympathetic to the measure, because the County Attorney has said that it's preempted by state law. But the County Council overrides the veto, so it's a law.
At which point plaintiffs sue to block the law. Defendants try to get the district court to certify the case to the Hawaii Supreme Court. Denied. Defendants try to avoid summary judgment. Rejected. Motion granted. Defendants appeal, and try to get the Ninth Circuit to certify the case or to reverse the grant of summary judgment.
Rejected again. District court decision affirmed in its entirety.
I point out to my students that having federal subject matter jurisdiction is sometimes very favorable to one particular side of the dispute. This is a good example. Defendants desperately want this case in Hawaii state court, with its particular perspective on these things. Plaintiffs, however, want federal court, and are able to both get and keep the adjudication there.
That makes a huge difference.