I did the cartoon when I was in Buffalo working for the Buffalo News and US News and World Report. It was based, as best as I can recall, on pure conjecture on my part about the strange movements of the American populace and what might be a plausible though unlikely future trajectory.
Much to my surprise, when I moved to D.C., I discovered that there was a conspiracy theory about this exact scenario afoot here, and it was called the EXACT SAME NAME: “The Plan.” I wondered if that name could possibly have derived from this cartoon somehow, and after about two minutes of fruitless searching, I decided doubtful. But highly highly strange indeed. Also discovered that other websites have comment threads even more off-topic than mine!