A few years ago I was on a short term mission project with about 80 other college kids. I did my own reserch and found similar results. The only real surprise was the girl from Boston who said "Twonic"
It's nice to see that someone actually has enough time on his hands to create this study.
Now we need to correlate this hugh and series issue with red/blue states.
The map tells us little about politics. "Black belt" counties in the lower Mississippi Valley, the one remaining area of Democrat strength in the South, are as much "Coke" drinkers as is the Texas Panhandle, where most counties went for Bush by 4:1 margins. The map does show internal migration of recent decades. Note that southeast Florida is "soda" country, probably reflecting the influx of retirees from New York and New Jersey. The plurality of "soda" in Arizona is probably attributable to Californians and Northeasterners migrating there.