They also don't seem to understand, as apocryphally attributed to Napoleon: "An army travels on its stomach". Middle America is called the bread basket for a reason, and without supplies coming in from the Red states, what exactly do they plan to eat? Fresh food will dry up fast, packaged foods will be used quickly. Does Bob think that the coastal cities can survive purely by fishing the oceans empty?
One of the disadvantages the South had in the Civil War was that, despite being agricultural, a lot of that production was geared toward cotton and tobacco. Food and fuel are probably even above ammunition when it comes to keeping an army fit for combat. Another rebel disadvantage: lack of industrial capacity or adequate supplies of gunmetal (Confederate weapons often substituted brass for steel, which was much more prone to deformation and expansion than steel). I don't think Bob has even thought to consider that the requirements for feeding and equipping his hypothetical coastal elite army against the mayonnaise ghouls. Bob and his ilk apparently never touched an RTS. Simplified as they may be, Warcraft and C&C put one important thing forward: wars are won through control of resources.
