from the article:

That electoral map, the one that shows the results of the 2016 election by county, has significant military meaning. The blue votes are concentrated in cities, which cannot feed themselves. As Chairman Mao said, “Take the countryside and the cities will fall.” Nor can they be supplied from the sea, because most of the people in the military are Trump supporters, which means the red side will get most of the ships and planes. The military problem is really quite simple, and need involve virtually no shooting or destruction. You just put the cities under siege and wait for the starving people to come out. It won’t take long.